'ion  Conipend: 


FSSE\TIALS0FAN\T()M\ 

ChAS.  B.  NANCRhiJE ,  M.  13, 


"^ 


I     /  *^  f 


/  y  '  u/* 


The  N< 


ME 


New  i 
Denti 
new 
of  B 
Oper, 
ment 
Pock 
full  f 


im 


Columbia  (Hnitoersftp 
mtljeCitpofl^fttjgDrk 

COLLEGE  OF 

PHYSICIANS  AND  SURGEONS 

LIBRARY 


o;' 


-r 


lur.h  Auchincloss 


andard 


RY 


J>1H-U1NL»    HLH  1  l^lNt    XVCVlom-'* 


Surgery, 
her  with 
inst  etc.; 
Diseases, 
»f  Treat- 
Vmerican 
bound  in 
0  net. 


//  contains  a  maximum  amount  of  matter  in  a  minimum 
space  and  at  the  Io<west  possible  cost* 

This  book  contains  double  the  material  in  the  ordinary  students'  dic- 
tionary, and  yet,  by  the  use  of  a  clear,  condensed  type  and  thin  paper  of  the 
finest  quality,  is  only  i^  inches  in  thickness..  It  is  bound  in  full  flexible  leather, 
and  is  just  the  kind  of  a  book  that  a  man  will  want  to  keep  on  his  desk  for  con- 
stant reference.  The  book  makes  a  special  feature  of  the  newer  words,  and 
defines  hundreds  of  important  terms  not  to  be  found  in  any  other  dictionary.  It 
is  especially  full  in  the  matter  of  tables,  containing  more  than  a  hundred  of 
great  practical  value,  including  new  tables  of  Tests,  Stains  and  Staining  Methods. 
A  new  feature  is  the  inclusion  of  numerous  handsome  illustrations,  many  of 
them  in  colors,  drawn  and  engraved  specially  for  this  book. 

"  I  must  acknowledge  my  astonishment  at  seeing  how  much  he  has  condensed  within  rela- 
tively small  space.  I  find  nothing  to  criticise,  very  much  to  commend,  and  was  interested  in 
finding  some  of  the  new  words  which  are  not  in  other  recent  dictionaries." — Roswell  Park, 
Professor  cf  Principles  and  Practice  of  Surgery  and  Clinical  Surgery,  University  of  Buffalo. 

"  I  congratulate  you  upon  giving  to  the  profession  a  dictionary  so  compact  in  its  structure, 
and  so  replete  with  information  required  by  the  busy  practitioner  and  student.  It  is  a  necessity 
as  well  as  an  informed  companion  to  every  doctor.  It  should  be  upon  the  desk  of  every  prac- 
titioner and  student  of  medicine."— John  B.  ^\vRVU-^,Professor  of  Surgery  and  Llimcal 
Surgery,  I^orth  luestern  University  Medical  School,  Chicago. 

W.  B.  SAUNDERS  &   CO.,  Publishers, 

925  Walnut  Street,  Philadelphia. 


Third  Edition,  Revised  Complete  Vocabulary 

THE 

AMERICAN  POCKET 

MEDICAL  DICTIONARY 

EDITED   BY 

W.  A.  NEWMAN    BORLAND,  A.M.,  M.  D., 

Assistant  Obstetrician  to  the  Hospital  of  the  University  of  Pennsylvania. 

THIRD  EDITION,  REVISED. 

Bound  in  Full  Leather,  Limp,  with  Gold  Edges.    Price,  $1.00  net; 
with  Patent  Thumb  Index,  $1.25  net. 


The  book  is  an  absolutely  new  one.  It  is  not  a  revi- 
sion of  any  old  work,  but  it  has  been  written  entirely  anew 
and  is  constructed  on  lines  that  experience  has  shown  to  be 
the  most  practical  for  a  work  of  this  kind.  It  aims  to  be 
complete,  and  to  that  end  contains  practically  all  the  terms 
of  modern  medicine.  This  makes  an  unusually  large  vocabu- 
lary. Besides  the  ordinary  dictionary  terms  the  book  contains 
a  wealth  of  anatomical  and  other  tables.  This  matter  is 
of  particular  value  to  students  for  memorizing  in  preparation 
for  examination. 

"  This  dictionary  is,  beyond  all  doubt,  the  best  one  among  pocket  diction- 
aries."— St.  Louis  Medical  and  Surgical  Journal. 

"  This  is  a  handy  pocket  dictionary,  which  is  so  full  and  complete  that  it  puts 
to  shame  some  of  the  more  pretentious  volumes." — Journal  of  the  American 
Medical  Association. 

"This  is  the  first  pocket  dictionaiy  worthy  of  the  consideration  of  the  pro- 
fession. It  is  just  the  kind  of  a  book  students  have  needed  for  many  years,  for 
it  contains  the  most  modern  words,  and  the  definitions  are  sufficiently  ample." — 
Ohio  Medical  Journal. 

"  This  is  one  of  the  handiest  little  dictionaries  for  the  pocket  that  we  have  yet 
seen.  Its  definitions  are  short,  concise,  and  complete,  so  that  it  contains  within 
a  small  space  as  many  words,  satisfactorily  defined,  as  are  found  in  some  of  the 
much  larger  volumes." — American  Medico- Surgical  Bulletin. 

*•  This  is  the  nicest  thing  in  the  way  of  a  pocket  dictionary  we  have  seen." — 
Chicago  Clinical  Review. 

W.  B.  SAUNDERS  &  CO,,  Publishers, 

925  Walnut  Street,  Philadelphia. 


ESSENTIALS 


OF 


ANATOMY. 


Since  the  issue  of  the  first  volume  of   the 
Saunders  Question=Compends, 

OVER  175,000  COPIES 

of  these  unrivalled  publications  have  been  sold. 
This  enormous  sale  is  indisputable  evidence 
of  the  value  of  these  self-helps  to  students 
and  physicians. 


SAUNDERS'  QUESTION-COMPENDS*  No*  3, 


ESSENTIALS  OF  ANATOMY 


INCLUDING    THE 


ANATOMY  OF   THE   VISCERA 

ARKANGEU    IN    THE    FORM    OF 

QUESTIONS  AND  ANSWERS 

PREPARED    ESPECIALLY    FOR 

STUDENTS  OF  MEDICINE 


BY 

CHARLES  B.  NANCREDE,  M.D. 

Professor  of  Surgery  and  of  Clinical  Surgery  in  the  University  of  Michigan 
Emeritus  Professor  of  General  and  Orthopedic  Surgery,  Philadelphia  Poly- 
clinic; Senior  Vice-President  of  tVie  American  Surgical  Association; 
Corresponding  Member  of  the  Royal  Academy  of  Medicine, 
Rome,  Italy ;  Member  of  the  American  Acad- 
emy of  Medicine,  etc. 


SIXTH  EDITION,  THOROUGHLY  REVISED 

BY 

FRED   J.  BROCKWAY.  M.D. 

Assistant   Demonstrator  of  Anatomy,  Columbia  University,  New  York 


PHILADELPHIA 

W.    B.    SAUNDERS 

925  Walnut  Street 

1899 


Copyright,  1899, 
By  W.  15.  SAUNDERS. 


C{/n2s 


ISII 


PRESS  OF 


ELECTROTVPED    BY 
WESTCOTT    i   THOMSON.    PHILA.  W.    B.    SAUNDERS.    PHILA. 


PREFACE  TO  SIXTH  EDITION. 


In  revising  "  The  Essentials  of  Anatomy "  the  general 
outline  and  arrangement  of  the  former  editions  have  been 
preserved,  some  new  matter  has  been  added,  a  few  small  cuts 
have  been  discarded  or  replaced  by  larger  ones,  descriptions 
and  statements  liave  been  corrected  to  accord  with  recent 
works,  and  many  small  words  have  been  inserted,  adding  to 
the  clearness  of  description.  The  revision  has  been  made 
with  a  desire  to  promote  the  aims  of  the  book  as  set  forth 
by  the  author  in  his  preface  to  the  first  edition. 

Fred  J.  Brockway. 


PREFACE  TO  FIRST  EDITION. 


The  author  has  endeavored  in  this  little  book  to  embody 
only  those  facts  which  have  appeared  to  him  to  be  really  the 
"  essentials  of  anatomy ;  "  not  that  he  considers  it  likely  that 
the  student  will  master  every  minute  detail  therein  contained, 
but  he  believes  that  the  knowledge  gained  by  a  study  of  this 
wr)rk  will  enal)lo  the  future  practitioner,  during  the  remainder 
of  his  ])rofessional  life,  to  recall  such  general  impressions  as 
will  render  intelligible  current  medical  literature,  or  even  the 
more  elaborate  monographs,  and  will  at  once  suggest  ivhere  to 

11 


1 2  PREFACE. 

consult  his  anatomical  text-books  for  such  terms  or  facts  as 
may  have  become  indistinct  through  lapse  of  time. 

While  this  book  cannot  replace  the  larger  anatomical  works, 
sufficient  descriptive  matter  has  been  introduced  to  enable  the 
student  to  refresh  his  memory  of  the  more  numerous  facts 
learnt  in  the  lecture  and  dissecting  room,  or  from  his  "  Gray  " 
or  other  text-book,  differing  in  this  respect-from  most  of  the 
works  of  its  class,  which  are  little  more  than  a  list  of  names, 
without  any  distinctive  facts  connected  with  them  to  aid  the 
student  in  the  difficult  task  of  acquiring  a  knowledge  of  a 
branch  of  medical  study  almost  solely  dependent  upon  the 
unassisted  powers  of  the  memory. 

Conciseness,  rather  than  elegance  of  diction,  has  been  the 
aim,  so  that  all  words  such  as  the  articles  "  a,"  "  an,"  "  the.'' 
have  been  omitted,  except  where  absolutely  necessary. 

Recognizing  that  a  work  of  this  kind  should,  as  far  as  pos- 
sible, conform  to  that  text-book  most  commonly  used,  the  last 
edition  of  Gray's  Anatomy  has  been  chosen  as  the  chief 
authority,  although  free  use  has  been  made  of  the  works  of 
Quain,  Leidy,  Bock,  Allen,  Morris  0)i  the  JouUs,  Starr  On 
Diseases  of  Children  (dentition).  Tomes  Dental  Anatomy, 
Potter,  Frey,  Holden,  Politzer,  H.  Thompson,  Astley  Cooper 
On  the  Breast,  and  original  work  of  one  of  the  author's  former 
students. 

The  author  would  here  acknowledge  his  obligations  and 
return  his  thanks  to  Prof  Joseph  Leidy,  of  the  University  of 
Pennsylvania,  for  the  kind  permission  to  reproduce  numerous 
cuts  from  the  first  edition  of  his  Anatomy,  and  to  Dr.  F.  M. 
Varrell  for  much  valuable  assistance  in  the  correction  of 
proof. 

Charles  B.  Nancrede. 


CONTENTS. 


PAGE 

Introduction 17 

Bones  of  the  Head 22 

The  Frontal  Bone 22 

The  Parietal  Bones 25 

The  Occipital  Bone ' 27 

The  Sphenoid  Bone 31 

The  Temporal  Bones 35 

The  Ethmoid  Bone 40 

The  Nasal  Bones 43 

The  Superior  Maxillary  Bones 43 

The  Lacrimal  Bones 48 

The  Malar  Bones 49 

The  Palate  Bones 50 

The  Inferior  Turbinated  Bones 52 

The  Vomer • 53 

The  Inferior  Maxillary  Bone 54 

The  Sutures  and  Fontanelles 57 

The  Cerebral  Fossae 58 

The  Orbital  Cavities 61 

The  Nasal  Fossae 66 

Bones  of  the  Trunk 69 

The  Vertebral  Colunm 69 

The  Ilyoid  Bone 78 

The  Thorax 78 

The  Sternum      80 

The  Ribs 80 

The  Pelvic  Bones      83 

The  Pelvis 88 


14  CONTENTS. 

PAGE 

Bones  of  the  Upper  Extremity 89 

Tlie  Arm 95 

The  Forearm 97 

The  Hand 102 

Bones  of  the  Lower  Extremity 106 

The  Thigh 106 

The  Patella 109 

The  Leg 110 

The  Foot 113 

The  Articulations 117 

The  Articulations  of  the  Trunk 119 

The  Articulations  of  the  Upper  Extremity 126 

The  Articulations  of  the  Lower  Extremity 132 

Muscles  and  Fasciae 140 

Muscles  of  the  Head 142 

Muscles  of  the  Neck 145 

Palatal  Kegion 148 

Vertebral  Eegion 149 

Muscles  of  the  Back 150 

Muscles  of  the  Abdomen 156 

Muscles  of  the  Thorax 159 

Muscles  of  the  Shoulder  and  Arm  .        161 

Muscles  of  the  Forearm 163 

Fascia?  of  the  Hand 167 

Muscles  of  the  Hand 168 

Muscles  of  the  Lower  Extremity 169 

Muscles  of  the  Leg 175 

Fascire  of  the  Foot 178 

Muscles  of  the  Foot 179 

The  Vascular  System 181 

The  Arteries 186 

Surgical  Anatomy  of  the  Arteries 211 

The  Veins 213 

The  Lymphatics 220 

The  Nervous  System 221 

The  Brain 224 

Cranial  Topography 237 

The  Spinal  Cord 239 

The  Cranial  Nerves 241 


CONTENTS.  15 

PAGE 

Tlie  Spinal  Nerves 248 

Tlie  Thoracic  Nerves 252 

The  Sympathetic  System 256 

Visceral  Anatomy 259 

Tlie  Digestive  Organs * .  259 

The  Teeth 260 

The  Mouth 263 

The  Pharynx 267 

The  Esophagus 269 

The  Stomach 270 

The  Small  Intestine 272 

The  Large  Intestine 274 

The  Liver 276 

The  Pancreas 283 

The  Ductless  Glands 284 

The  Spleen 285 

The  Thyroid  Gland 286 

The  Thymus  Gland 287 

The  Sui:>rarenal  Capsules 288 

The  Abdominal  Cavity 289 

The  Peritoneum 292 

Organs  of  Voice  and  Resj)iration        295 

The  Larynx 295 

The  Trachea  and  Bronchi 301 

The  Lungs 303 

The  l^leurae 308 

The  Urinary  Organs 312 

The  Kidneys 312 

The  Ureters 317 

The  Bladder 318 

The  Male  Urethra 321 

Tlie  Female  Urethra 323 

The  Male  Generative  Organs 324 

The  Penis 325 

The  Testes  and  their  Coverings 327 

The  Female  Organs  of  Generation 331 

The  Vagina 333 

The  Uterus  and  its  A  ppendages      334 

The  Mammary  Glands 339 


16  CONTENTS. 

PAGE 

The  Organs  of  Sense 340 

The  Skin  and  its  Appendages      340 

Tlie  Organs  of  Taste 342 

The  Organs  of  Smell 343 

The  Eye 345 

The  Appendages  of  the  Eye 359 

The  Ear       363 

The  External  Ear 303 

The  Middle  Ear,  or  Tympanum 365 

The  Internal  Ear,  or  Labyrinth  372 

Anatomy  of  Inguinal  Hernia 381 

Femoral  Hernia 383 

The  Perineum  and  Ischiorectal  Regions 385 


Essentials  of  Human  Anatomy. 


Give  the  derivation  and  meaning  of  the  term  anatomy. 

From  two  (ireek  words,  av^i,  apart,  and  -ziir^ivj^  to  cut,  literally 
meaning  dissection;  but  it  is  used  to  indicate  the  study  of  the 
physical  structure  of  organized  bodies. 

How  is  human  anatomy  divided  ? 

Into  two  great  divisions,  viz. :  1.  General  or  descriptive  anat- 
omy, which  deals  with  the  separate  parts  of  the  human  body. 
Histology  is  a  part  of  general  anatomy  in  w^liich  the  structural 
elements  are  studied,  usually  with  the  aid  of  a  microscope.  2. 
Surgical  or  regional  anatomy  describes  the  relations  which  in- 
dividual parts — muscles,  nerves,  arteries,  etc. — bear  to  each 
other. 

What  is  osteology  ? 

A  subdivision  of  general  anatomy,  describing  the  number, 
form,  structure,  and  uses  of  the  bones. 

What  is  the  chemical  composition  of  osseous  tissue  (bone)  ? 

About  one-third  (33.3)  is  organic  or  animal  matter,  resolv- 
able into  gelatin  after  prolonged  boiling,  with  traces  of  chon- 
drigen  (the  proximate  principle  of  cartilage),  and  two-thirds 
inorganic  (GO. 7),  consisting  of  calcium  phosphate  (tribasic) 
51.04,  calcium  carbonate  11.30,  calcium  fluorid  2,  magnesium 
phosphate  1.10,  and  sodium  chlorid  with  traces  of  sodium 
dioxid  1 .20.  Either  the  organic  or  the  inorganic  matter  may  be 
removed  without  affecting  the  form  of  the  bone  ;  the  former, 
by  exposure  to  heat  with  free  access  of  air,  after  which  slight 
force  will  reduce  the  bone  to  powder ;  the  latter,  by  steeping 
in  dilute  hyclrochloric  acid,  which  will  render  a  bone  as  pliable 
as  a  strip  of  rubl^er.  In  rickets  only  about  20  per  cent,  of 
lirae-salts  are  deposited  and  80  per  cent,  of  animal  matter. 
2  17 


18  ESSENTIALS  OF  HUMAN   ANATOMY. 

Does  an  increase  of  the  mineral  constituents  take  place  in  old 
age? 

No,  although  this  is  a  common  statement  in  text-books ; 
for  wliile  e(|ual  />«//i>-  of  young  and  old  bones  do  show  marked 
differences  in  the  proportion  of  earthy  and  animal  constituents, 
etjual  iccif/ht.s  do  not,  so  that  the  elasticity  in  youth  and  the 
brittleness  in  age  depend  upon  the  greater  sponginess  of  text- 
ure in  young  bones. 

Is  bone  a  homogeneous  substance  ? 

No  ;  for  while  the  exterior  is  composed  of  a  comjKicf  (hard, 
ivory)  layer,  the  inner  portions  are  formed  of  spongy  or  cancel- 
f'>fis  tissue  ;  the  interior  of  long  bones  is  hollow,  forming  the 
medullary  (^marrow)  canal.  The  compact  tissue  occurs  upon 
the  exterior  or  in  the  shaft  of  long  bones  where  "  cross-strain  " 
is  greatest;  whereas  cancellous  tissue  enables  the  articular  ends 
of  the  bones  to  be  large  for  security,  yet  light,  this  tissue  being 
capable  of  bearing  enormous  pressure,  but  incapable  of  bearing 
much  •*  cross-strain."  Probably  all  solid  bone  is  a  definite 
compound. 

Describe  the  microscopic  structure  of  bone. 

In  transverse  section,  with  a  low  power,  a  number  of  holes 
will  be  observed,  averaging  -^^  inch  in  diameter,  surrounded 
by  a  series  of  tolerably  concentric  circles,  con.sisting  of  an 
interrupted  series  of  dark  spots.  With  high  powers  the  holes, 
called  Haversian  canals  for  the  passage  of  vessels,  are  seen  to 
be  surrounded  by  a  series  of  concentric  rings,  termed  lamellae, 
while  the  dark  spots  reveal  themselves  as  cavities  in  the  bone, 
called  Incmiee,  intercommunicating  with  each  other  and  the  cen- 
tral Haversian  canal  by  means  of  delicate  radiating  lines,  called 
canalicuU:  this  aggregation  of  structures  is  called  an //ra-c/*- 
sian  system.  The  lacunae  contain  bone-corpuscles,  processes  of 
which  extend  into  the  canalicnU.  As  each  Haversian  system 
communicates  by  its  canaliculi  with  those  of  its  neighbor  and 
exterior  of  the  bone,  all  portions  of  its  most  compact  tissue 
and  the  medullary  canal  freely  intercommunicate  and  receive 
nutrient  material.  As  these  systems  are  circular,  they  would 
leave  interspaces  where  not  in  contact ;  but  these  gaps  are  filled 
up  by  layers  of  bone  with  tamellst  and  canaliculi,  which  por- 
tions are  called  interstitial  lamellae.     In  addition  to  the  concen- 


ESSENTIALS  OF   HUMAN   ANATOMY.  lU 

trie  laineUce  around  the  Haversian  canals,  other  lamellae  are 
found  arranged  concentrically  to  the  circumference  of  the 
bone,  called  circumferential  or  fundamental  lameUst.  All  lamellae 
are  thin  plates  of  bone  ;  they  are  held  together  by  \\\ki  l)erforat- 
i](g  fbcrs  of  Sltarpei/. 

What  are  the  periosteum  and  the  endosteiim  ? 

The  periosteum  is  a  membrane  serving  as  a  scaffolding  to 
enable  the  blood-vessels  to  reach  all  portions  of  the  exterior  of 
the  bone  except  its  articular  ends  and  the  points  of  attachment 
of  strong  tendons.  It  is  composed  of  two  portions  :  the  outer 
or  fibrous  layer  is  dense  and  protective  ;  the  inner  layer  is  vas- 
cular and  contains  many  osteoblasts,  or  bone-forming  cells,  upon 
which  the  growth  in  thickness  of  the  bone  depends. 

The  term  endosteum  is  applied  to  the  delicate  connective- 
tissue  lining  of  the  medullary  and  cancellous  cavities  which 
contains  numerous  bone-forming  cells. 

Describe  the  medulla  or  marrow. 

There  are  two  varieties, ^e/fo?c  and  red:  yellow  marrow  occurs 
in  adult  long  bones,  and  is  OG  per  cent,  fat  ;  red  marrow  contains 
72  per  cent,  of  water  and  a  trace  of  fat.  It  is  found  in  all  fetal 
and  infantile  bones  ;  in  the  adult  it  is  in  the  short  and  flat  bones, 
ends  of  long  bones,  vertebra),  cranial  bones,  sternum,  and  ribs. 
Marrow  possesses  five  kinds  of  cells:  fat-cells;  marrow-cells 
proper,  resembling  leukocytes  ;  nucleated  red  cells  ;  cells  con- 
taining red  corpuscles  ;  and  giant-cells. 

Do  bones  receive  blood  only  from  vessels  in  the  periosteum  ? 

Xo  ;  for  the  medullary  tissue  of  all  long  bones  receives  a 
good-sized  artery  (the  medullary  artery),  whichobliquely  pene- 
trates the  compact  tissue,  after  which  it  divides  into  two  main 
branches,  one  ascending,  the  other  descending,  in  the  medullary 
canal ;  the  veins  chiefly  emerge  through  numerous  openings 
near  the  articular  ends  of  the  bones. 

Describe  the  process  of  ossification. 

There  are  two  methods,  viz.  :  (1)  in  membrane  and  subperios- 
teolly ;  (2)  in  cortihge.  The  bones  of  the  vertex  of  the  skull 
and  those  of  the  face,  with  few  exceptions,  are  formed  in  mem- 
brane ;  the  base  of  the  skull  and  the  other  bones  of  the  body 
and  limbs  are  formed  in  cartilage.    (1)  In  the  former  the  bone- 


20  ESSENTIALS  OF  HUMAN   ANATOMY. 

forming  cells  (^osteoblasts')  arrange  themselves  along  the  thick 
bundles  of  fibrous  tissue  which  radiate  from  the  center  of  the 
future  bone  ;  by  the  deposition  of  lime-salts  in  these  osteo- 
blasts the  deposit  of  bone  shoots  out  in  needle-like  rays  to- 
ward the  circumference.  (2)  A  deposit  of  bone  begins  at  one 
spot  of  the  cartilage,  the  jjrimari/  cutter.  The  shaft  is  formed 
from  this.  Just  before  ossification  commences  the  cartilage- 
cells  enlarge  and  arrange  themselves  in  rows.  Lime-salts  are 
deposited  in  the  matrix  between  the  rows,  forming  columns 
which  enclose  oblong  spaces  containing  cartilage-cells,  called 
the  primari/  areolae.  Now  ossification  proper  commences  by 
the  ingrowth  from  the  periosteum  of  buds  of  young  connective 
tissue  covered  with  bone-forming  cells,  which,  after  causing 
absorption  of  the  cartilage,  become  converted  into  bone. 

Of  how  many  bones  is  the  adult  human  skeleton  composed  ? 

Two  hundred,  including  the  os  hyoides,  but  excluding  the 
teeth,  Wormian  bones,  all  sesamoid  bones  except  the  patellae, 
and  the  ossicles  of  the  middle  ear. 

Into  what  classes  are  bones  divided  ? 

Long  hones,  as  femur,  tibia,  etc.,  about  90  in  number;  flat, 
as  those  of  the  vault  of  the  skull,  scapula,  ribs,  patella,  about 
40;  irregular,  as  the  vertebra3,  usually  symmetrical,  about  40; 
and  short,  such  as  the  carpal  and  tarsal  bones,  numbering  30. 

What  are  Wormian  bones  ? 

Irregular  fragments,  developed  from  supplementary  centers, 
situated  at  the  junction  of  two  or  more  cranial  sutures,  where, 
during  infancy,  a  membranous  interval  existed,  viz.,  a  fontan- 
elle.  From  their  triangular  form  they  are  often  called  ossa 
triqnetra. 

What  are  sesamoid  bones  ? 

Those  developed  in  the  substance  of  tendons,  whereby  the 
muscles  obtain  additional  leverage — /.  e.  power ;  the  patella 
and  pisiform  are  classed  with  these  bones. 

Of  what  parts  do  long  bones  consist,  and  what  are  their  uses  ? 

Of  a  shaft  (body,  diaphysis),  two  articular  extremities,  and 
various  processes ;  they  are  developed  in  cartilage,  from  one 
principal  and  one  or  more  additional  (epiphyseal)  centers  of 


ESSENTIALS  OF  HUMAN  ANATOMY.  21 

ossification  ;  they  serve  as  supports  and  levers  for  power  and 
progression. 

Where  are  short  and  flat  bones  employed,  and  why  ? 

In  the  carpus  and  tarsus,  where  strength  with  limited  motion 
is  required.  The  flat  bones  consist  of  two  layers  of  compact 
tissue  with  interposed  cancellous  tissue,  called  diploe ;  they 
serve  for  protection  and  muscular  attachment. 

What  facts  are  noted  concerning  the  medullary  arteries? 

1.  Medullary  arteries  run  from  the  knee  and  toward  the  el- 
bow. 2.  The  secondary  center  from  which  the  artery  runs  is 
the  first  to  appear.  3.  The  epiphysis  first  to  appear  is  last  to 
unite. 

How  are  bony  prominences  and  cavities  named  ? 

Each  variety  offers  an  articular  and  a  non-articular  division. 

Give  the  names  and  characteristics  of  the  chief  articular 
processes. 

Head^  a  convex  smooth  projection,  with  a  constriction  or 
neck  beneath;  found  in  freely  moving  joints. 

Condyles^  double  projecting  processes,  may  have  a  constric- 
tion or  neck — i.  e.  neck  of  condyle  of  jaw. 

Mention  some  of  the  non-articular  processes,  with  their 
meanings. 

Trochanters^  short  projecting  levers  near  articulations  to  fa- 
cilitate rotation  of  the  bone  on  its  long  axis. 

Tuhei'osities,  roughened,  broad  prominences. 

Tuhrrcles,  similar  to  the  above,  but  small  with  reference  to 
the  size  of  the  bone. 

Spines  and  spinous  processes,  more  or  less  pointed  projections. 

Apophysis^  strictly  speaking,  any  bony  process  which  develops 
from  the  primary  center  of  ossification,  commonly  used,  how- 
ever, for  any  process,  even  if  an  epiphysis,  after  it  has  coossi- 
fied  with  the  mass  of  the  bone.  Certain  descriptive  terms  are 
used  :  r^^7/yo.s■,  without  a  fellow  ;  coracoid^  like  a  crow's  beak  ; 
mastoid,  like  a  nipple  ;  rostrum.,  a  beak  ;  styloid,  pen-like  ;  squa- 
mous, like  a  scale  ;  vaginal,  ensheathing  ;  clinoid,  like  a  bed. 

Name  some  of  the  articular  cavities  of  bone. 

Cotyloid,   wlien   they   resemble   a   deep   cup ;    glenoid,  when 


22  ESSENTIALS  OF  HUMAN   ANATOMY. 

tlicy  liave  a  shallow  cup-form  ;  trochlear,  pulley-like ;  fdcet, 
when  smooth,  like  one  of  the  surfaces  of  a  cut  iiem  ;  siyinoid, 
when  (-shaped,  resembling  the  old  Greek  letter  lor  v"- 

What  are  the  principal  non-articular  cavities  called  ? 

Fossff,  shallow  depressions  ;  sinuses,  deep  cavities,  communi- 
cating with  the  exterior  by  small  openings  ;  c/roovrs^  long,  nar- 
row depressions  ;  Jissures,  cracks  ;  iiofchcs,  deficiencies  of  edges 
of  l)ones  ;  foramina,  holes  through  bones  for  transmission  of 
nerves,  etc. 

What  is  a  diaphysis  ? 

The  main  portion  of  a  bone  (shaft  in  a  long  bone,  body  in 
an  irregular  one)  between  the  epqjhi/ses. 

What  is  an  epiphysis  ? 

A  supplementary  center,  usually  to  provide  for  growth  in 
h'iKjfli,  developed  in  cartilage,  which  remains  separated  by  a 
layer  of  cpipliyscal  cartilage  until  the  growth  of  the  bone  is 
completed,  when  it  co"6ssifies  with  the  eJie/phi/sis,  and  all  further 
growth  ceases.  Epiphyseal  centers  appear  after  birth  :  they 
coossify  in  the  inverse  order  of  their  appearance,  except  that 
of  the  lower  end  of  the  fibula.  This  process  of  coossification 
commences  about  puberty,  and  the  last  to  unite  are  those  of 
the  upper  end  of  the  tibia  and  the  vertebral  bodies — as  late  as 
twenty-five  years. 

BONES   OF   THE   HEAD. 

Name  the  bones  composing  the  skull. 

They  are  twenty-two  in  number:  eight  of  which  (cranial) 
compose  the  brain-case,  viz.,  one  frontal,  two  parietal,  two  tem- 
poral, one  sphenoid,  one  occipital,  and  one  ethmoid  ;  fourteen 
are  facial,  two  superior  maxillary,  two  malar,  two  nasal,  two 
lacrimal,  two  palatal,  two  inferior  turbinated,  one  vomer,  and 
one  inferior  maxillary,  or  mandible  ;  the  ethmoid  of  the  cra- 
nium also  enters  largely  into  the  formation  of  the  nasal 
cavities. 

The  Frontal  Bone. 

Of  what  parts  does  this  bone  consist  ? 

Of  a  vertical  and  a  horizontal  portion,  meeting  at  an  angle 
of  60°. 


THE  FRONTAL  BONE. 


23 


Describe   the  points   on  the    outer  surface  of  the  vertical 
portion  (Fig.  1). 

On  each  side  of  the  median  line  are  two  fronfdl  eminences^ 
between  which  are  the  remains  of,  or  the  obliterated  (jnetoplc) 
frontal  suture,  leaving  a  slight  linear  dejiressiou,  which,  above 
the  root  of  the  nose,  terminates  in  a  rounded,  projecting  nasal 


A^asal    process 
Fig.  1.— Frontal  bone,  outer  surface  (Gray). 


eminence  (glabella).  Extending  from  this  on  each  side  arc  two 
curved,  rounded  supprciliari/  ridgrs,  situated  behind  which,  be- 
tween tliG  two  tables  of  the  skull,  lie  the  frontal  siimsrs  (Fig. 
2).  The  junction  of  the  vertical  and  horizontal  portions  forms 
on  each  side  a  curved  margin,  the  supra-orhit<tl  arrJi,  notched 
or  perforated  toward  its  m\\(\v  part  by  the  supra-orhital  iiotr/i, 
or  foramen,  transmitting  the  artery  ;ind  nerve  of  the  same 
name.  Each  orbital  margin  terminates  by  two  stout  processes, 
calhsd  internal  anf/ular  and  external  <in(jnl<(r  processes.  Hcitween 
the  two  inner  projects  tin;  n(fsal  process,  in  the  rough,  uneven 
space,  (•all(!d  the  nasal  notrJi  ;  the  under  surface  of  the  nasal 
process   presents    a   median    ridge,   nasal   spine,   between   two 


24 


ESSENTIALS  OF  HUMAN    ANATOMY. 


grooves.      The   inargin    of   the   external    angular   process   ex- 
tends upward   as  the   iiifnior   temporal  ridge   (Fig.    1). 

Describe  the  points  on  the  cerebral  surface. 

In   the  median   line  a  frordid  sulcus  (Fig.  2)  (for  the  longi- 
tudinal sinus)  exists,  whose  edges  coalesce  below  to  form  the 


iiy\?^<^i^W^^ 


J        ||       '  Fipn  r<iiJ  b^tf   of  No*' 
TiiUuJaT  rlaU  qf  Mli-^.uy  J        J        jrrnunj  v-iH  if  IfocrT    -' 


nut 
Na*r  '  process 


with  PerprTL.-i 

Fig.  2.— Frontal  bone,  inner  surface  (Gray). 

frontal  cr^.?^,  which  terminates  as  a  notch,  or  perhaps  complete 
foramen  csecmn  (blind),  which  when  pervious  transmits  a  small 
vein. 

Describe  the  horizontal  portion. 

This  consists  of  two  orbital  ^^lates  of  a  triangular  outline, 
separated  by  a  quadrilateral  ethmoidal  notch  (for  articulation 
with  the  ethmoid).  A  shallow  lacrimal  fossa  (for  the  gland)  ex- 
ists at  the  outer  part  of  the  orbit,  also  a  trochlear  fossa  or  some- 
times a  small  tuhercle  at  the  anterior  inner  part  for  the  pulley 
of  the  superior  obli((ue  muscle.  Several  half  cells  are  seen 
along  the  margins  of  the  ethmoidal  notch,  which  complete  the 
ethmoidal  cells  when  the  ethmoid  is  in  position,  as  well  as  two 


THE   PARIETAL   BONES.  25 

grooves^  which  are  likewise  converted  into  the  anterior  and^^os- 
terior  ethmoidal  canals^  the  former  for  the  nasal  nerve  and  an- 
terior ethmoidal  vessels,  the  latter  for  the  posterior  ethmoidal 
vessels.  On  each  side  of  the  nasal  process  open  the  frontal 
sinuses  (absent  in  infants),  a  part  of  the  nasal  cavities,  into 
which  each  opens  by  the  infiuuUhiihim.  The  cerebral  surfaces 
of  both  vertical  and  horizontal  portions  present  numerous  de- 
pressions for  the  convolutions  of  the  brain,  and  branching 
grooves  for  the  anterior  meningeal  arteries. 

What  centers  of  ossification  has  this  bone  ? 

Two  develop  near  the  orbital  arches,  in  membrane,  at  the 
seventh  or  eighth  fetal  week. 

With  what  bones  does  it  articulate  ? 

With  two  parietal,  the  sphenoid,  the  ethmoid,  two  nasal,  two 
superior  maxillary,  two  lacrimal,  and  two  malar— twelve  in  all. 

What  muscles  arise  from  it  ? 

The  corrugator  supercilii,  orbicularis  palpebrarum,  and  tem- 
poral on  each  side. 

The  Parietal  Bones. 

Describe  a  parietal  bone  ? 

It  is  of  a  quadrilateral  form,  convex  externally,  concave  in- 
ternally. It  presents  four  borders,  four  angles,  and  two  sur- 
faces. Its  upper  serrated  border  forms  with  its  fellow  the 
sarjittal  snture ;  the  anterior  alternately  bevelled  margin  joins 
the  frontal,  forming  part  of  the  coronal  suture;  the  inferior 
border  presents  three  parts,  bevelled  in  front  for  the  wing  of 
the  sphenoid,  next  for  the  squama,  then  serrated  for  the  mas- 
toid ;  the  posterior  serrated  border  articulates  with  the  occip- 
ital (lamhdoid  suture).  The  antero-superior  angle  is  at  the 
junction  of  the  coronal  and  sagittal  sutures  ;  the  antero-inferior 
angle  fits  under  the  wing  of  the  sphenoid  and  internally  pre- 
sents a  groove  or  canal  for  the  anterior  branch  of  the  middle 
meningeal  artery;  the  postero-supi^rior  angle  marks  the  apex 
of  the  lambdoid  suture;  the  postero-inferior  angle  articulates 
with  the  mastoid  aiid  internally  shows  a  groove  for  part  of 
the   lateral   sinus. 

The  external  surface  shows  near  its  center  the  parietal  emi- 


26 


ESSENTIALS   OF   HUMAN   ANATOMY. 


uencc  or  />o.s'.s-.  Curving  across  the  middle  of  the  bone  are  the 
upper  and  Jnin-r  frmporal  Unca  or  ridges,  for  attaelnnent  of  the 
temporal  I'ascia  and  muscle  ;  and  near  the  posterior  superior 
angle  is  often  a  pdiiital  foramni  transmitting  a  small  vein  to 
the  superior  longitudinal  sinus  (sometimes  a  small  branch  of 
the  occipital  artery). 

The  inner  surface  is  concave,  and  its  deepest  part  is  the  parietal 


<^tem.J}o>-ci.l  6o/ue        TT^i^ 


Fig.  o. — Left  parietal  bone,  external  surface. 


fossa.  It  is  marked  with  numerous  smooth  digital  depressions 
for  the  brain  convolutions,  with  a  shallow  h«df  groove  (Fig.  4) 
along  the  superior  border  for  the  superior  longitudinal  sinus, 
and  several  Pacchionian  depressions.  There  are  furrows  for 
arteries  and  often  the  opening  of  the  parietal  foramen. 

How  is  it  developed  ? 

In  membrane,  from  two  centers  which  coalesce  at  the  emi- 
nence, appearing  at  the  fifth  to  sixth  fetal  week. 


THE  OCCIPITAL   BONE. 


27 


Give  muscular  attachments  and  articulations. 

Temporal  muscle  :  artieuhites  with  five  bones,  the  opposite 
parietal,  occipital,  temporal,  frontal,  and  sphenoid. 

The  Occipital  Bone. 

Of  what  parts  does  this  bone  consist  ? 

The  occipital  bone  is  a  curved,  trapezoidal  plate  situated  at 
the  posterior  part  aud  base  of  the  skull.  It  is  convex  posteriorly 
and   concave   anteriorly.     At  birth   the  bone   consists  of  fonr 


Anal" 


^,Ani  Sup. 
Aualc 


Ant.  LfcT.AneiU 


Fig.  4.— Left  parietal  bone,  internal  surface  (Gray). 

pieces.  At  its  lower  and  anterior  part  i's  tlie  foramen  mairnum. 
I'ehind  this  is  a  fahiilar  j^oj'fion  (squarao-occij»ital ).  the  upper 
part  of  which  may  be  separate,  the  iiifrrjxirirfd/  fxttir  (bone  of 
the  Tricas)  ;  the  lower  part  is  i<iipr(i-orrip!f(t].  On  either  side 
of  the  foramen  are  c/mdijlnr  porfionsi  (ex-oocipitals),  and  in  front 
is  tlu;  basilar  porfion  fbnsi-occipital).  The  bone  may  be  de- 
scribed by  its  fetal  divisions  or  as  a  whole;  in  the  latter  ease 
it  presents  two  surfaces,  four  borders,  and  four  anf:;lcs.  The 
cxtfrnal  surface  (V\^.   5)   presents  midway  between  the  sum- 


28 


ESSENTIALS  OF  HUMAN   ANATOMY. 


iiiit  and  foramen  magnum  the  external  occipitnl  protuher- 
(tiice  (inion)  for  attachment  of  the  ligamentiim  nuchas  and 
biventer  cervicis  muscle.  Descending  from  it  to  the  fora- 
men is  tlie  median  external  occipital  crest.  The  ligamentum 
nuchas  is  attached  to  it  also.  Passing  outward  from  the  pro- 
tuberance on  each  side  to  the  lateral  angle  is  the  s(q)erior  curved 
line,  or  superior  nuchal  line.      Internally  and  above  this  line 


1^   Surfare  for  Occp    f^^. 


'  oramtn, 


M<i. 


r.lrs    , 
a,  J.  lig  '. 


H^^ 


suptnion 

iONSTBlCTOa 


Fig.  5.— Occipital  bone,  outer  surface  (GrajO- 

is  often  the  supreme  curved  line  for  attachment  of  the  mid- 
dle portion  of  the  occipito-frontalis  aponeurosis.  Between 
these  two  lines  the  bone  is  smooth  and  dense,  the  torus  trans- 
versus  (transverse  bulge).  From  the  middle  of  the  external 
crest  a  semicircular  inferior  curved  line  runs  outward  on  each 
side  and  bends  sharply  downward  to  the  jugular  process.  To 
the  superior  curved  line  is  attached  internally  the  trapezius  and 
externally  the  occipitalis  and  sterno-mastoid  muscles.  Below 
this  line  internally  is  a  large  impression  for  the  complexus  ; 
then  come  the  superior  oblique  and  splenius  capitis  above  and 
externally.  To  the  inferior  line  and  depressions  below  it  are 
attached  the  rectus  posticus  minor  internally  and  the  major 


THE  OCCIPITAL  BONE. 


29 


externally.  The  foramen  mafjnum  is  an  oval  aperture,  30  to 
35  mm.  in  its  long  axis.  It  transmits  the  medulla  and  its  mem- 
branes, the  spinal  part  of  the  spinal  accessory  nerves,  vertebral 
and  spinal  arteries,  and  occipito-axial  ligaments.  It  is  broader 
behind  than  in  front,  and  bevelled  internally.  The  condyles  are 
on  either  side  of  the  foramen  for  articulation  with  the  atlas. 
They  converge  in  front,  are  reniform,  with  smooth,  oblong,  ar- 
ticular surfaces  looking  downward  and  outward.  Internally  is 
a  depression  for  the  insertion  of  a  check  ligament.  Behind  the 
condyle  is  tha  posterior  condj/hir  fossa .  often  containing  the  jjos- 
terior  condylar  foramen  for  transmission  of  a  vein.  External 
to  the  condyle  is  the  jugular  process^  presenting  ajugidar  notch 
in  front,  which  forms  a  part  of  the  jugular  fossa.  The  under 
surface  presents  an  eminence  (paramastoid),  the  attachments 
of  the  rectus  capitis  lateralis  muscle  and  of  a  lateral  ligament ; 


S  a  fie  Pi 


Fig.  6.— Occipital  bone,  inner  surface  (Gray). 

the  outer  surface  is  a  rough,  cartilaginous  facet  for  articulation 
with  th(;  tcmponil  bone.  The  basilar  process  projects  forward 
and  upward  in  t'nmt  of  the  foramen.     It  is  narrow  and  thick 


30  1:^^SE^T1ALS  OF  HUMAN    ANATOMY. 

in  front.  Below  it  presents  the  pharyugaal  spine  for  the  attach- 
ment of  the  superior  constrictor  of  the  pharynx,  and  impres- 
sions for  the  rectus  capitis  anticus  major  and  minor  muscles. 

Describe  the  cerebral  surface  of  the  bone  (Fig.  6). 

It  is  deeply  concave,  divided  into  fuar  fossae,  by  a  crucial 
grooved  ridge,,  crossing  at  a  prominent  iittevnal  occipital  protuber- 
ance ;  the  two  upper  fossae  lodge  the  occipital  lobes  of  the  cere- 
brum, the  two  lower,  the  hemispheres  of  the  cerebellum  ;  the 
two  lateral  and  superior  grooves  lodge,  respectively,  between 
the  layers  of  the  tentorium  cerebelli  and  the  falx  cerebri,  the 
lateral  and  part  of  the  superior  longitudinal  sinuses  ;  the  inferior 
groove,  or  intrmal  occipital  crest,  has  attached  the  Jalx  cerebelli, 
and  lodges  in  two  grooves,  the  occipittd  sinuses.  Between  the 
sinuses  is  the  vermiform  fossa.  Perforating  the  base  of  the 
condyle  downward  and  outward  is  the  canalis  hypoglossi,  some- 
times double,  ending  in  the  anterior  condylar  foramen  transmit- 
ting the  hypoglossal  nerve,  emissary  veins,  and  a  branch  of  the 
ascending  pharyngeal  artery.  The  upper  surfaces  of  the  jugu- 
lar processes  are  deeply  grooved  for  the  lateral  sinuses.  The 
upper  surface  of  the  basilar  process  shows  the  basilar  groove 
for  the  medulla,  and  laterally  a  half  groove  for  the  inferior 
petrosal  sinus. 

Angles.— The  superior  angle  is  the  apex  of  the  tabular  por- 
tion; the  inferior  angle  is  the  end  of  the  basilar  process;  the 
laf(  rid  angles  correspond  to  the  ends  of   the  superior  curved 

liiu's. 

Borders. — The  superior  borders  between  the  upper  and  lateral 
angles  form  the  lambdoid  suture,  occipito-parietal ;  the  upper 
part  of  an  inferior  border  extends  from  the  lateral  angle  to  the 
jugular  process,  masto-occipital ;  the  lower  part  articulates  with 
the  petrous  portion  of  the  temporal,  petro-occipital  suture,  which 
presents  posteriorly  the  Jugular  fossa  (foramen  lacerum  pos- 
terius). 

Attachment  of  muscles. 

Thirteen  pairs,  as  mentioned  above. 

With  what  bones  does  it  articulate  ? 

Two  parietal,  two  temporal,  sphenoid,  and  atlas ;  six  in  all. 


THE  SPHENOID  BONE. 


31 


What  centers  of  ossification  has  it  ? 

Four  in  the  tabular  portion  ;  upper  pair  in  lueuibrane  (eighth 
fetal  week),  one  for  the  basilar,  and  one  for  each  condyloid 
portion  in  cartilage  (seventh  or  eighth  fetal  week)  ;  in  four 
pieces  at  birth,  in   the  sixth  year  it  forms  one  bone. 

The  Sphenoid  Bone. 

What  are  its  divisions  and  where  is  it  situated  ? 

A  hody^  two  lessi'i-  icinys^  two  greattr  iciiiys,  two  pttryyoid 
plates,  two  sjmLoiis  2)i'0cesses,a,nd  six  cUmnd  processes  ;  it  is  situ- 
ated at  the  base  of  the  cranium,  articulating  with  all  the  other 
cranial  bones,  and  five  or  seven  of  the  face.  Named  from  a 
Greek  word  meaning  ivedge;  in  the  process  of  development  this 
is  its  function.  It  also  somewhat  resembles  a  bat  with  extended 
wings. 

Describe  the  body  of  the  sphenoid. 

It  is  large,  cuboidal,  hollowed  out  (in  adult)  into  the  sphenoi- 
dal  sinuses  (Fig.  8).     ISuperiurly,  in  front,  is  a  sharp  projecting 


Uiddlo   CUiioid  procci  •  j  t    c 

Fu^tcruir  CU.Twid  proccst  \      _         ^      •     ' 

-~^  -^  V     V       Croovt  Jat 


lo'rtf. 


lorarmn  OpUcu 

Ant.,  9V S^u.TU»eialFCift 

J*t/ravuin  JJctu  uJu  rn 

,  OuaU 

0         S^.iuaivi, 


Fig.  7.— Sphenoid  bone,  superior  surface  (Gray). 

ethmoidal  spine  for  the  ethmoid  ;  behind  this,  a  smooth  surface 
with  a  longitudinal  cnninence  producing  two  shallow  (plf<trf<>ri/ 
yrooves^  bounding  which  bc^hind  is  a  transverse  optic  groove  (  Fig. 
7),  lodging  the  commissure  of  the  optic  nerves,  terminating  in 


32  ESSENTIALS   OF   HITMAN    ANATOMY. 

two  optic  f ova  mi  iia  for  the  optic  nerves  and  ophthalmic  arteries. 
Behind  the  groove  is  tlie  projecting  olicari/  procrss^  forming  the 
anterior  boun(hiry  of  a  marked  depression,  the  aclla  turcica, 
lodging  the  pituitary  gland  and  circular  sinus.  On  each  side, 
in  front,  are  two  small  projecting  middle  clinoid  proca^afs,  while 
behind  is  a  square-shaped  plate,  dorsum  scJIac,  terminating  at  the 
superior  angles  by  the  posterior  clinoid  processes,  and  to  them 
are  attached  portions  of  the  tentorium  cerebelli.  The  sides 
of  this  bony  plate  are  notchi.d  for  the  sixth  pair  of  nerves,  and 
the  superior  surface,  or  dorsnni.  with  a  broad,  shallow  depres- 
sion, slopes  obliquely  downward  and  backward,  becoming  con- 
tinuous with  the  basilar  j)ortion  of  the  occipital  bone  ;  it  sup- 
ports the  pons  Varolii.  A  broad  cavernous  groove  for  the 
carotid  artery  and  cavernous  sinus  exists  on  either  side  of  the 
body.  Posteriorly  to  the  outer  side  of  the  groove  is  the  liugida, 
and  internally  the  petros(d  process.  The  posterior  rough  quad- 
rilateral surface  articulates  with  the  basilar  portion  of  the 
occipital  bone. 

A  vertical  plate,  the  sphenoidal  crest  (Fig.  8),  projects  from 
the  anterior  surface  of  the  body,  forming  part  of  the  nasal  sep- 
tum, having  the  irregular  openings  of  the  sphenoidrd  sinuses  on 
either  side  (absent  in  child),  which  open  either  into  the  poste- 
rior ethmoidal  cells  or  directly  into  the  nasal  cavities.  Two 
thin  curved  sphenoidal  turhinated  bones  narrow  these  orifices 
to  a  round  opening  at  their  upper  part ;  these  plates  articulate 
with  the  palate  and  ethmoid  bones. 

The  inferior  surface  presents  in  the  center  the  rostrum  for 
the  vomer,  having  on  either  side  a  thin  plate,  the  vaginal 
process,  articulating  with  the  ala;  of  the  vomer,  and  the  pterijgo- 
palatine  grooves,  which  by  articulation  Avith  the  sphenoidal 
processes  of  the  palate  bones  are  converted  into  the  pterygo- 
palatine canals  for  the  pterygo-palatine  vessels  and  pharyngeal 
nerve. 

Describe  the  greater  wings. 

Two  strong  processes  arising  from  the  sides  of  the  body, 
curving  upward,  outward,  and  backward.  The  concave  c^r^- 
br(d  surface  of  each  wing  forms  part  of  the  middle  fossa  of  the 
skull,  presenting  a  circular  opening  at  its  antero-internal  part, 
the  foramen  rotundum  for  the  second  branch  (superior  maxillary) 
of  the  fifth  pair  of  nerves ;  a  second  larger  ovoidal  foramen, 


THE  SPHENOID   BONE. 


33 


the  foramen  ovale  (Figs.  7  and  8),  transmitting  the  third  (infe- 
rior maxillary)  division  of  the  same  nerve  (sometimes  the  small 
petrosal  nerve)  and  small  meningeal  artery,  while  piercing  the 
sharp,  pointed,  posterior  extremity  of  the  wing,  or  spinous 
process^  is  seen  a  short  canal  (sometimes  double),  the  foramen 
.sjjinosum,  for  the  passage  of  the  middle  meningeal  artery,  its 
venae  comites  and  the  nervus  spinosus,  a  recurrent  branch  of 
the  inferior  maxillary  nerve.  Occasionally  the  foramen  Vesalii^ 
on  the  inner  side  of  the  oval  foramen,  is  present,  transmitting 
a  small  vein. 

The  external  surface  presents  the  infratemporal  ridge  divid- 
ing the  temporal  from  the  zygomatic  fossa ;   at  its  posterior 


p-terygoU,  Midyt 


InterTutl  Ttt      

ncfmtilu,r    /i/foc 

Fig.  8.— Sphenoid  bone,  anterior  surface  (Gray). 

part  the  spinous  process  (Fig.  8)  gives  origin  to  the  tensor  tym- 
pani  muscle  and  the  internal  lateral  ligament  of  the  lower  jaw. 
The  anterior  or  orhital  surface,  smooth,  quadrilateral,  forming 
part  of  the  outer  orbital  wall,  is  bounded  above  by  a  serrated 
edge  for  articulation  with  the  frontal,  below  by  a  rounded  bor- 
d(;r  which  enters  into  the  formation  of  the  splicno-mdxillnri/ 
Jissure ;  internally  it  aids  in  the  formation  of  the  sjihrnoidol 
fissure  and  has  a  notch  at  the  upper  part  of  the  inner  border 
for  a  bran(;]i  of  tin;  lacrimal  artery  ;  a  small  spine  at  its  lower 
part,  for  part  of  the  origin  of  the  external  rectus  muscle  ;  ex- 


34  ESSENTIALS  OF  HUMAN  ANATOMY. 

ternally  it  presents  a  serrated  articular  margin  for  the  malar 
bone,  and  (at  times)  one  or  more  external  orbital  forarnina. 
The  circumference  has  been  described  above. 

Describe  the  lesser  wings. 

These  (processes  of  Ingrassias)  two  thin,  triangular  proc- 
esses arise  from  the  upper  and  lateral  parts  of  the  body,  and 
project  transversely  outward,  to  terminate  internally  in  the  an- 
terior clinoid processes  (Fig.  7),  externally  in  sharp  points.  By 
their  anterior  borders  they  articulate  with  the  orbital  plates 
of  the  frontal  bone,  while  by  their  posterior  free  margins  they 
divide  the  anterior  from  the  middle  cerebral  fossa.  Between 
their  roots  on  each  side  is  the  optic  foramen  for  the  optic  nerve 
and  ophthalmic  artery.  Each  inferior  surface  forms  on  either 
side  the  back  part  of  the  orbital  roof,  and  the  upper  boundary 
of  the  sphenoidal  fissure,  or  foramen  lacerum  anterius.  which  is 
bounded  internally  b}' the  .sphenoid  body,  and  inferiorly  by  the 
orbital  margin  of  the  greater  wing,  externally  by  the  frontal, 
transmitting  the  third,  fourth,  ophthalmic  branch  of  the  fifth, 
and  sixth  nerves,  with  the  ophthalmic  veins,  filaments  from  the 
cavernous  sympathetic  plexus,  also  branches  of  the  lacrimal 
and  middle  meningeal  arteries,  with  a  process  of  the  dura 
mater. 

Describe  the  pterygoid  processes. 

These,  consisting  of  an  internal  and  external  plate  separated 
behind  by  a  notch — the  ptrrygoid  fossa  for  the  internal  ptery- 
goid muscle — descend  on  each  side  perpendicularly  from  the 
junction  of  the  greater  wing  with  the  body.  At  the  base  of 
the  internal  plate  is  the  scaphoid  fossa,  giving  origin  to  the 
tensor  palati  muscle,  above  which  is  the  orifice  of  the  Vidian 
canal.  Internal  to  these  is  the  pterygoid  tubercle.,  below  that  a  sul- 
cus and  a  processus  tubff:  for  the  Eustachian  tube,  and  then  a  con- 
cave edge  for  the  superior  constrictor ;  this  plate  terminates  by 
a  curved  hamidar  process^  around  which  plays  the  tendon  of 
the  tensor  palati  muscle.  The  external  pterygoid  plate  has 
arising  from  its  outer  surface  the  external  pterygoid  muscle. 
The  triangular  notch  below  has  fitting  into  it  the  tuberosity  of 
the  palate  bone. 

Name  the  bones  with  which  the  sphenoid  articulates. 

The  other  seven  cranial  bones  and  five  facial,  viz.,  the  two 


THE  TEMPORAL  BONES.  35 

palate,  two  malar,  and  vomer,  and  sometimes  the  two  superior 
maxillae. 

By  how  many  centers  of  ossification  is  this  bone  developed  ? 

By  fourteen  centers :  two  for  the  internal  pterygoid  plates 
in  memhmne,  two  for  the  greater  wings  and  external  pterygoid 
plates,  two  for  the  lesser  wings,  two  for  the  anterior  part  of 
the  body,  two  for  the  sphenoidal  turbinated  bones,  two  for  the 
posterior  part  of  the  body,  two  for  the  Ungvlse,  appearing  from 
the  second  fetal  month  to  the  third  year  in  cartilage.  The 
bones  completely  unite  by  the  twentieth  year. 

What  muscles  have  their  origin  from  the  sphenoid  bone? 

The  temporal,  external  and  internal  pterygoids,  superior 
phar3nigeal  constrictor,  tensor  palati,  levator  palpebrae,  ob- 
liquus  superior,  superior,  internal,  external,  and  inferior  recti. 

The  Temporal  Bones. 

Where  are  they  situated? 

At  the  sides  and  base  of  the  skull. 

What  parts  does  each  bone  present  for  examination? 

A  squamous  (scale-like),  a  mastoid  (nipple-like),  and  2b  petrous 
(stony  hard)  portion. 

Describe  the  squamous  portion. 

The  main  portion  is  an  irregularly  semicircular,  smooth 
plate,  grooved  posteriorly  for  the  deep  temporal  arteries,  con- 
vex externally,  concave  internally,  and  here  grooved  for  the 
middle  meningeal  artery,  with  digital  drpressions  for  the  cere- 
bral convolutions.  Posteriorly,  a  curved  ridge  (part  of  tem- 
poral) is  seen.  Springing  from  its  lower  part  is  the  long, 
twisted,  arched  zygomatic  process.,  arising  by  three  roots,  viz., 
a  posterior,  forming  part  of  the  temporal  ridge,  one  running 
directly  inward  in  front  of  the  glenoid  fossa,  convex,  covered 
with  cartilage,  forming  the  emiiicntia  articularis.,  and  a  middle, 
the  outer  margin  of  the  glenoid  fossa.  The  obli((uely  trans- 
verse, glenoid  fossa  for  the  condyle  of  the  lower  jaw,  is  divided 
into  two  parts  by  the  Glaserian  fssurr  (Fig.  0),  which  trans- 
mits the  tympanic  artery,  and  lodges  the  processus  gracilis  of 


36 


ESSENTIALS  OP^  HUMAN   ANATOMY. 


the  malleus :  part  of  the  parotid  gland  occupies  that  portion 
posterior  to  the  fissure.  Parallel  to  this  fissure,  in  the  retiring 
angle  between  the  squamous  and  petrous  portions,  is  the  open- 
ing of  the  canal  of  Huguier  for  the  chorda  tympani  nerve.    At 


lUiifot 


Fig.  9.— Left  temporal  bone,  outer  surface  (Gray). 


the  junction  of  the  articular  eminence  with  the  zygomatic 
process  is  the  tubercle  for  the  external  lateral  ligament  of  the 
lower  jaw. 

Describe  the  mastoid  portion. 

This  projects,  rough,  and  perforated  by  numerous  foramina, 
from  the  postero-inferior  portion  of  the  bone — one  foramen, 
tlie  mastoid,  transmits  a  vein  from  the  lateral  sinus  and  a  small 
branch  of  the  occipital  artery.  The  interior  portion  of  the 
bone  contains  the  mastoid  cells,  lined  with  mucous  membrane 
continuous  with  that  of  the  tympanum.  The  conical  tip  is 
termed  the  mastoid  process,  upon  whose  inner  side  a  deep 
grooved  digastric  fossa  (Fig.  11)  exists  for  the  digastric  muscle, 
while  parallel,  but  more  internal,  lies  the  occipital  groove  (Fig. 
11),  lodging  the  artery  of  the  same  name.      A  deep  sigmoid 


THE  TEMPORAL   BONES. 


37 


fossa  (Fig.  10)  exists  on  the  inner  surface  of  the  mastoid 
portion  for  part  of  the  lateral  sinus,  in  which  can  be  seen 
the  inner  orifice  of  the  mastoid  foramen. 


p  fl,  rt  ^  fi«  / 


Diprettiun  fci  Dura-inattr 
Bieattu  AudUurin*  vrttfpnuj 


1  niiuuu  for  ^uperiar  S c^mUiTcuLir  C'u^Ji 

\^JIiatt^f   J'aUopii 

L  ^'^O^o-nirtq  for  S-nfaUr.r  PctTVtsi^Ntf^ 
Vevnsiufn  fax  CtctterLan  ganglion 
SrUtU  passed  tiraufA  Carotid  Canal 


Fig.  10.— Left  temporal  bone,  hmer  surface  (Gray). 

Describe  the  petrous  portion. 

This  is  a  dense  pyramidal  mass,  wedged  in  between  the 
sphenoid  and  occipital  bones,  containing  the  organs  of  hear- 
ing. Its  long  axis  is  directed  from  without  inward,  forward; 
and  a  little  downward.  Its  apex,  three  surfaces,  and  three 
borders  must  be  studied.  The  apex  (Fig.  10)  lies  in  the  angle 
formed  by  the  posterior  border  of  the  greater  sphenoidal  wing 
and  the  basilar  process  of  the  occipital,  forms  the  posterior 
and  external  boundary  of  the  foramen  lacerum,  and  presents 
the  internal  orifice  of  the  carotid  canal. 

The  base,  its  upper  half  covered  by  the  squamous  and  mas- 
toid portions,  presents  the  oval,  expanded  orifice  of  the  niratvs 
awJiforins  exfc/rnvs,  its  upper  margin  smooth,  but  surrounded 
for  the  greater  part  of  its  circumference  by  the  rough-edged 
(f(»r  the  cartilage  of  the  external  ear),  curved  plate  of  bone 
called  the  external  auditory  process. 


38  ESSENTIALS  OF   HUMAN   ANATOMY. 

The  anterior  surface  forming  the  posterior  part  of  the  middle 
cerebral  fossa  presents  an  eminence,  eminent ia  arcnata  (Fig.  10), 
near  the  center,  indicating  the  situation  of  the  vertical  semi- 
circular canal  of  the  ear ;  external  to  this  a  depression  over  the 
tympanum,  tegmen  tympani ;  a  shallow  groove  leading  back- 
ward and  outward  to  an  oblique  opening,  the  hiatus  Fallopii, 
for  the  great  superficial  petrosal  nerve  and  the  petrosal  branch 
of  the  middle  meningeal  artery  ;  a  smaller  groove  and  opening 
external  to  the  latter  for  the  small  superficial  petrosal  nerve ; 
the  termination  of  the  carotid  canal  near  the  apex  ;  above  this 
canal  a  shallow  depression  for  the  Gasserian  ganglion  of  the 
fifth  nerve ;  six  points  of  interest. 

The  posterior  surface  forms  the  anterior  part  of  the  posterior 
cerebral  fossa,  presents  about  its  center  the  large  orifice  of  the 
short  (about  four  lines)  meatus  auditorius  internus  directed  out- 
ward (closed  by  a  vertical  perforated  plate,  lamina  cribrosa), 
which  transmits  the  facial  and  auditory  nerves  (seventh  and 
eighth  cranial),  the  auditory  artery,  and  is  lined  by  the  dura 
mater ;  behind  the  meatus  is  a  small  slit  leading  to  the  aqiise- 
ductus  vestibuli,  transmitting  a  small  artery  and  vein,  and  lodg- 
ing a  process  of  the  dura  mater.  Above  and  between  these 
points  is  the  suharcuate  fossa,  which  lodges  a  process  of  the  dura 
mater  and  transmits  a  small  vein. 

The  inferior  (basilar)  surface,  from  apex  to  base,  presents  a 
rough  quadrilateral  surface  for  the  origin  of  the  tensor  tym- 
pani and  levator  palati  muscles ;  the  circular  orifice  of  the 
carotid  canal  (Fig.  11)  ascending  vertically,  then  abruptly 
passing  horizontally  forward  and  inward  for  the  passage  of  the 
internal  carotid  artery  with  its  sympathetic  nerve  plexus;  to 
the  inner  side  of  this — a  small,  triangular  opening,  the  aquse- 
ductus  cocJdese,  transmitting  a  vein  from  the  cochlea  to  the  in- 
ternal jugular;  behind  these  openings  a  deep  depression,  the 
Jugular  fossa  (Fig.  11),  which  with  the  jugular  notch  of  the 
occipital  bone  forms  the  Jugular  foramen,  transmitting  the  in- 
ferior petrosal  and  lateral  sinuses  and  between  them  the  ninth, 
tenth,  and  eleventh  cranial  nerves;  a  ^maW  foramen  for  Jacob- 
sons  ne7've,  a  branch  of  the  glosso-pharyngeal,  in  front  of  the 
bony  ridge  separating  the  carotid  canal  from  the  jugular  fossa ; 
on  the  outer  wall  of  the  jugular  fossa  a  small  foramen  for 
Arnold's  nerve  ;  posterior  to  the  jugular  fossa,  a  square-shaped, 
smooth  facet  for  articulation  with  the  jugular  process  of  the 


THE  TEMPORAL  BONES. 


39 


occipital ;  a  broad,  sheath-like,  bony  plate  extending  from  the 
carotid  canal  to  the  mastoid  process,  the  caginal procaas.  which, 
splitting  into  two  lamime,  partially  encloses  the  base  of  a  long, 
sharp  spine,  the  styhid  process,  from  which  arise  the  stylo- 
pharyngeus,  stylo-hyoideus,  and  stylo-glossus  muscles,  and  the 
stylo-hyoid  and  stylo-maxillary  ligaments  ;  between  this  process 
and  the  mastoid,  a  large  orifice,  the  stylo-mastoid  foramen,  for 
the  exit  of  the  facial  nerve,  and  the  entrance  of  the  stylo-mas- 
toid artery  ;  and,  finally,  between  the  vaginal  and  mastoid  proc- 


Ciinalspr Elista eJiian  tithe 
alii/'  Tcnsaf-tymf/qnimasclc 


LEVATOR      PAL 


Rcni^h  QutuLrilaUral Surface 
0£fninq  of  caroUJ-  canal 
Canal/for  Jacolfon'a  nerve 
Aijuf'diicrus  Corhlcic 
Cajuilfor  A  mold's  verve 
Ju^ultLr  fossa, 
\agi  na  I  jfraccss 
JSlyJnid  p  raeess 
Sti/lo-mastoi/J,  foramen 
tTiiytitnr  Si' r face 
Auricular  fisturc 


STVLO  -PM  A^rNOCUS 


Fig.  11.— Petrous  portion,  inferior  snrftice  (Gray). 


esses,  the  miricidar  fissure  for  the  exit  of  Arnold's  nerve,  a 
branch  of  the  pncumogastric. 

At  the  angle  formed  by  the  junction  of  the  petrous  and 
squamous  portions  two  camds  exist,  separated  by  a  thin,  bony 
septum,  the  septum  tnhae,  often  incorrectly  called  the  processus 
ror/df'(trif>nin's,  the  Upper  lodging  the  tensor  tympani  muscle, 
the  lower  being  the  bony  Knsfiiehiiin  fuhe. 


40  ESSENTIALS  OF  HUMAN   ANATOMY. 

What  additional  points  of  interest  do  the  borders  present? 

The  superior  is  grooved  for  the  superior  petrosal  sinus,  and 
has  attached  to  it  the  tentorium  cerebelli ;  the  posterior  has  a 
half-groove  which,  with  another  on  the  occipital,  accommodates 
the  inferior  petrosal  sinus. 

From  how  many  centers  is  this  bone  developed? 

From  ten  :  one  for  the  squamosal  and  zygoma  (in  mem- 
brane), four  for  the  petrous,  two  for  the  mastoid,  two  for  the 
styloid,  and  one  for  the  tympanic  plate  (all  the  latter  in  carti- 
lage), from  the  eighth  fetal  week  to  the  sixth  fetal  month — 
bone  cobssities  in  the  first  year,  except  the  styloid  process. 

With  what  bones  does  each  temporal  articulate? 

The  occipital,  one  parietal,  sphenoid,  one  malar,  and  the 
inferior  maxillary  :  five  bones. 

What  muscular  attachments  has  it? 

Sipiamoscd,  the  temporal ;  zygoma^  the  masseter  ;  the  mastoid 
portion  and  process^  the  occipito-frontal,  sterno-mastoid,  sple- 
nius  capitis,  trachelo-mastoid,  digastricus,  and  retrahens  aurem. 
Sti/Ioid,  the  stylo-pharyngeus,  stylo-hyoideus,  stylo-glossus. 
Petrons,  the  levator  palati,  tensor  tympani,  tensor  palati,  and 
stapedius  ;  fifteen  in  all. 

The  Ethmoid  Bone. 

Of  what  parts  does  this  bone  consist? 

Of  a  horizontal  cribriform  plate^  (sieve-like),  of  two  lateral 

masses^^  of  cells  depending  from  this  on  either  side  (Fig.  12), 
between  which  lies  i\iQ  p>erpendicular p)late'^ 
forming  part  of  the  septum  of  the  nose ; 
the  whole  bone  is  of  a  cuboidal  form. 

Describe  the  cribriform  plate. 

Springing  from  the  upper  surface  is  the 
crista  galli^  (cock's-comb),  a  vertical  plate 
running  from  before  backward,  whose  an- 
terior border  is   notched  to   complete  the 
bo^„'?,p,i?edo?v"w'."     foramen  ea-eum  of  the  frontal  bone^   Two 
deep,  longitudinal  olfactory  grooves,  for  the 
olfactory  bulbs,  lie  on  either  side,  their  floors  perforated  by  three 
rows  of  small  foramina,  for  filaments  of  the  olfactory  nerves ; 


THE  ETHMOID  BONE. 


41 


and  on  each  side  in  front  is  a  small  slit  for  the  nasal  branch 
of  the  ophthalmic  nerve ;  the  crest  gives  attachment  to  the 
falx  cerebri. 

Describe  the  perpendicular  plate  (Figs.  12  and  14). 

It  is  thin,  usually  deflected  to  one  or  other  side,  forms  part 
of  the  nasal  septum,  and  has  upon  each  side  numerous  grooves 
and  canals  to  accommodate  the  olfactory  nerve  filaments. 

Of  what  are  the  lateral  masses  formed?  (Figs.  12  and  13). 

Of  thin-walled  cavities,  the  ctlimoidal  cells,  three  sets,  whose 
outer  limits  make  the  os  j^lcinum^,  while  their  inner  walls  form 
part  of  the  nasal  fossae  ;  above  they  are  grooved  to  form  with 
grooves  on  the  frontal  the  two  ethmoidal  foramina.  The  upper 
outer  margins  of  each  mass  present  a  number  of  half-cells  com- 


Ufit/t   infMurbiiuiteJ  6, 

Fig.  13.— Ethmoid  bone,  outer  surface  of  ri},'ht  lateral  mass  (enlarged)  (Gray). 

pletely  closed  in  when  articulated  with  the  ethmoidal  notch  of 
the  frontal  bone  ;  posteriorly  are  also  half-cells  completed  by 
the  sphenoidal  turbinated  and  palate  bones  ;  again,  in  front 
and  below,  the  cells  are  completed  by  the  lacrimal  and  su- 
perior maxillary  bones;  inferiorly  an  irregular  hook-liko  plate 
projects,  the  unciform  procena'',  which  closes  in  the  upper  part 


42 


ESSENTIALS  OF  HUMAN   ANATOMY. 


of  the  orifice  of  the  antrum.  A  narrow,  oblique  fissure,  the 
anpcn'or  nasal  mfutns,  su])divides  the  inner  surface,  bounded 
above  by  the  thin  curved  anperior  turhuiated  hone^,  below  by 
the   convex   scroll-like  middle  turbinated  hone'']   the  posterior 


Fig.  14.— Perpendicular  plate  of  ethmoid  (enlarged),  shown  by  removing  the 

right  lateral  mass. 


celh  open  into  the  upper  part  of  this  fissure,  the  anterior  and 
middle  open  into  the  frontal  sinus  above,  and  into  the  middle 
nasal  meatus  below,  by  the  flexuous  infnndibulum.  The  mid- 
dle meatus  is  bounded  above  by  the  middle  turbinated  bone. 

How  many  centers  of  ossification  has  this  bone  ? 

Three :  one  for  each  lateral  mass  (fourth  to  fifth  fetal 
month)  ;  one  for  the  perpendicular  and  cribriform  plates  in 
cart  Huge  during  the  first  year ;  the  ethmoidal  cells,  completing 
the  bone,  form  about  the  fourth  or  fifth  year. 

With  how  many  bones  does  it  articulate? 

Fifteen  :  the  sphenoid,  two  sphenoidal  turbinated,  frontal, 
two  nasal,  two  superior  maxillary,  two  lacrimal,  two  palate, 
two  inferior  turbinated,  and  the  vomer.  No  muscles  are  at- 
tached. 


THE  SUPERIOR  MAXILLARY   BONES. 


43 


The  Nasal  Bones. 

Describe  them. 

They  are  of  oblong  form,  their  outer  surfaces  concave  from 
above  downward,  convex  from  side  to  side,  marked  by  many 
small  arterial  furrows  and  usually  presenting  at  their  centers 
a  single  or  double  venous  foramen.     Their  inner  surfaces  are 


fronVsci  oone 


/aroouefor     ^ 


Fig.  15  —Right  nasal  bone,  outer  Fig.  16.— Left  nasal  bone,  inner 

surface.  (Gray.)  surface. 

convex  from  above  downward  and  concave  from  side  to  side, 
traversed  longitudinally  by  a  groove^  sometimes  a  canal,  for  a 
branch  of  the  nasal  nerve  which  escapes  by  a  notch  about  the 
middle  of  the  lower  thin  margin.  Each  bone  presents  four 
borders. 

With  what  bones  does  each  nasal  bone  articulate  ? 

With  the  frontal,  ethmoid,  its  fellow  nasal,  and  the  superior 
maxillary.     It  has  no  muscular  attachments. 

How  is  each  developed? 

From  one  center  in  membrane  (eighth  fetal  week). 

The  Superior  Maxillary  Bones. 

Describe  them. 

Th(;y  ( acli  consist  of  a  hollow  body  and  four  processes ;  to- 
gether they  form  the  whole  upper  jaw. 

Describe  the  body. 

It   is   ciiboidal   in  form   and  hollowed  out  into  a  pyramidal 
cavity,  ihc  (tnfrinn  of  IJiyhniorr.   (Fig.    IS).      Of  its  four  svr- 


44 


ESSENTIALS  OF  HUMAN   ANATOMY. 


faces,  the  external  (facial),  directed  forward  and  outward,  pre- 
sents, just  above  the  incisor  teeth,  the  incisive  (myrtiform) 
/oss(t  (Fig.  17),  more  externally  the  larger  canine  fossa,  sepa- 
rated from  the  former  by  the  canine  eminence  formed  by  the 
socket  of  the  canine  tooth  ;  above  this  is  the  infra-orbital  fora- 
men, giving  egress  to  the  infra-orbital  artery  and  nerve ;  and 
above  this  surface  is  the  margin  of  the  orbit. 

The  posterior  surface  is  convex,  forms  part  of  the  zygomatic 
fossa,  has  about  its  center  several  apertures  of  the  posterior 
dental  canals  for  the  dental  vessels  and  nerves;  at  its  lower 
part  (especially  after  the  wisdom  tooth  is  formed)  is  a  rounded 


Ineisivf  fossor 


Posterior  Hfntal  Canah 


£laxilloLru  Tulerositii, 


•"'""■•   Micicsiiids. 

Fig.  17.— Left  superior  maxillary  bone,  outer  surface  (Gray). 

eminence,  the  maxillar?/  tuherosifi/  (Fig.  17),  which  articulates 
by  its  rou2:h  inner  surface  with  the  tuberosity  of  the  palate 
bone  ;  and  just  above  the  rough  surface  is  an  oblique  groove 
running  down  on  the  inner  side,  which  by  the  apposition  of 
the  palate  bone  forms  the  posterior  palatine  camtl  (Fig.  18). 
The  superior  (orbital  plate)  surface,  thin,  smooth,  and  trian- 
gular, forms  part  of  the  floor  of  the  orbit,  articulates  internally 
by  an  irregular  margin  (from  behind  forward)  with  the  palate 
bone.  OS  planum  of  the  ethmoid  and  lacrimal ;  externally,  by 


THE  SUPERIOR   MAXILLARY   BONES. 


45 


its  smooth,  rounded  edge,  it  helps  to  form  the  spheno-maxilhxry 
fissure  (sometimes  articulating  in  front  with  the  orbital  plate 
of  the  sphenoid)  ;  anteriorly  it  forms  part  of  the  orbital  mar- 
gin. At  the  middle  of  the  outer  border  of  this  surface  is  the 
deep  infra-orbital  groove  (Fig.  17),  which  in  front  becomes  a 
canal  of  the  same  name,  opening  by  the  infra-orbital  foramen  ; 
small  canals  branching  from  this  pass  into  the  substance  of  the 
anterior  wall  of  the  antrum — the  anterior  and  middle  dental 
canals;  at  the  inner  forepart  of  this  orbital  surface  are  a  lacri- 
mal notch  and  a  minute  depression  for  the  origin  of  the  inferior 
oblique  muscle  of  the  eye. 

The  internal  surface^  unequally  divided  horizontally  into  two 
parts  by  the  palate  process  (Fig.  18),  forms  above  this  part  of 


Ethmoid 

Infnuif  TariinaUd 

Palate 


i*ii^«d 


Ani.  N^asal  Spilt* 


Bristle 

paused  ihrouak 
Ant- palat.  Canal 

Fig.  18.— Left  superior  maxillary  bone,  inner  surface  ^Gray). 

the  outer  wall  of  the  nasal  fossae ;  below,  a  portion  of  the 
mouth.  The  nasal  surface  presents  a  large  irregular  opening 
into  the  antrum,  above  which  are  irregular  cellular  cavities 
closed  in,  when  articulated,  by  the  ethmoid  and  lacrimal 
bones.  B(;h)W  the  opening  is  the  smooth  surface  forming  part 
of  the  inferior  meatus  of  the  nose;  behind,  a  ronc/li  surface  for 
the  ])ahite  bone  with  a  groove  passing  from  above  downward 
and   forward,  the  posterior  palatine,  which,  closed  in   by  the 


4G  ESSENTIALS  OF  HUMAN   ANATOMY. 

palate  bone,  forms  the  posterior  palatine  canal ;  in  front,  a 
deeper  vertical  groove,  which  by  the  apposition  of  the  lacri- 
mal and  inferior  turbinated  bones  forms  the  lacrimal  canal  for 
the  nasal  duct ;  and  still  more  anteriorly  the  well-marked  horiz- 
ontal, inferior  turbinated  crest,  for  the  inferior  turbinated  bone. 

Describe  the  antrum  of  Highmore  (maxillary  sinus). 

It  is  triangular,  with  its  apex  directed  outward  formed  by  the 
malar  process,  its  base  forming  the  outer  nasal  wall,  and  opens,  in 
the  fresh  state,  by  a  small  orifice  of  the  size  of  a  probe  point  into 
the  middle  nasal  meatus.  In  the  non-articulated  bone  there  is 
a  large  irregular  opening,  which  is  narrowed  when  articulated 
by  portions  of  the  palate,  ethmoid,  inferior  turbinated,  and 
sometimes  the  lacrimal  bones.  On  its  posterior  walls  are  the 
posterior  dental  canals,  while  its  floor  presents  several  conical 
prominences,  produced  by  the  fangs  of  the  first  and  second 
molar  teeth ;  sometimes  the  floor  is  actually  perforated.  The 
walls  are  very  thin. 

Describe  the  malar  process. 

It  is  a  rough,  triangular  eminence,  concave  on  its  facial  and 
zygomatic  surfaces,  and  roughly  serrated  above  for  the  malar 
bone. 

Describe  the  nasal  process. 

This  is  thick  and  triangular,  rising  upward,  inward,  and  back- 
ward, witli  an  external  concave  smooth  surface,  an  internal 
surface  articulating  with  the  frontal  above  and  by  a  rough  sur- 
face with  the  ethmoid  ;  below  this  is  the  transverse  ridge-like 
superior  turbinated  crest  for  the  middle  turbinated  bone.  Next 
comes  a  smooth,  concave  surface,  part  of  the  middle  nasal 
meatus;  then  the  inferior  turbinated  crest  (see  antf^-,  and, 
most  inferior  of  all,  the  concavity  forming  part  of  the  inferior 
nasal  meatus.  The  anterior  border  is  thin  and  serrated  for 
articulation  with  the  nasal  bone  ;  the  jxjsterior  border  is  thick, 
and  grooved  for  the  lacrimal  duct,  which  is  directed  backward 
and  a  little  outicard;  where  the  outer  margin  of  the  groove 
joins  the   orbital  surface  is  the  lacrimal  tvbercle. 

Describe  the  alveolar  process. 

This  is  thick  and  spongy,  with  eight  cavities  of  varying 
depth,  that  for  the  canine  tooth  being  deepest,  and  those  for 
the  molars  widest  and  subdivided. 


THE  SUPERIOR   MAXILLARY   BO^'ES. 


47 


Describe  tlie  palate  process. 

It  is  a  horizontal  plate  (Figs.  IS  and  VJ),  thickest  in  front, 
forms  most  of  the  roof  of  the  mouth  and  floor  of  the  nostril ; 
has  an  upper  and  a  lower  concave  surface.  In  front,  upon  the 
upper  surface,  is  the  upp(;r  orifice  of  the  anterujr  palatine  canal, 
which  leads  to  a  fossa  formed  between  the  two  bones,  trans- 
mitting" the  anterior  palatine  vessels  through  the  forantlna  of 


J'^or  ft  rnc'^v 
of'  St^nsetv^ 


of  ScOJ'pCtt 


Post.jjtilaHne   (irjittl^ 


Accessory  jjeilatino. 

Fig.  19.— The  palate  and  alveolar  arch  (Gray). 

Stensen,  the  naso-palatine  nerves  passing  through  the  inter- 
maxillary suture  by  i\\G  foramina  of  Scarpa;  upon  the  under 
surface  is  a  longitudinal  groove  (sometimes  a  canal),  leading 
from  the  posterior  palatine  canal,  for  the  posterior  palatine 
vessels  and  nerve,  while  in  front  is  seen  the  lower  orifice  of 
the  anterior  palatine  foana  presenting  four  openings  ;  the  iniier 
border  is  thickened  into  a  ridge  on  the  upper  surface,  forming 
the  nasal  crest,  which  rnns  higluir  in  front,  called  the  incisor 
crest,  and   then   forms  the  anterior  nasal  spine. 


4:6 


ESSENTIALS  OF  HUMAN   ANATOMY. 


How  is  this  bone  developed? 

Probably  by  four  centers  ;  it  develops  so  early,  immediately 
after  the  clavicle  and  mandible,  that  its  number  of  centers  is 
uncertain.  There  seem  to  be  the  malar  j^ortion,  orbito-facial, 
palatine,  and  a  premaxillary  carrying  the  incisor  teeth.  The 
antrum  commences  at  the  fourth  fetal  month. 

With  what  bones  does  it  articulate? 

With  the  frontal,  ethmoid,  nasal,  malar,  lacrimal,  inferior 
turbinated,  palate,  vomer,  with  the  other  superior  maxillary, 
and  sometimes  with  the  sphenoid. 

Give  the  muscular  attachments. 

Orbicularis  palpebrarum,  obliquus  oculi  inferior,  levator 
labii  superioris  alseque  nasi,  levator  labii  superioris,  levator 
anguli  oris^  compressor  nasi,  depressor  alae  nasi,  dilator  naris 
posterior,  masseter,  buccinator,  internal  pterygoid,  and  orbic- 
ularis oris. 

The  Lacrimal  Bones. 

What  is  their  shape  and  where  are  they  situated? 

They  are  two  small  bones  situated  at  the  front  part  of  the 

inner  wall  of  the  orbit,  resembling  in  form,  thinness,  and  size 
u.'ii\rrc7iM  a   finger-nail,   hence    called   os   unguis. 

The  external  orbital  surface  presents 
a  vertical  ridge  giving  origin  to  the 
tensor  tarsi  muscle,  in  front  of  which 
is  a  concave  longitudinal  groove  form- 
ing part  of  the  lacrimal  canal  below, 
lodging  the  lacrimal  sac  above.  Be- 
low is  the  hamular  process  articulating 
with  the  superior  maxillary  bone,  as- 
sisting to  form  the  lacrimal  canal.  A 
depressed  furrow  is  seen  on  the  nasal 
sin-face  corresponding  to  the  ridge  ex- 
ternally ;  the  surface  in  front  forming 
part  of  the  middle  nasal  meatus,  the 
posterior  closing  in  the  anterior  eth- 
This  bone  also  presents  foio'  horders. 

With  what  bones  does  it  articulate? 

With  the  frontal,  ethmoid,  superior  maxillary,  and  inferior 
turbinated. 


In^fi'^- 


Fig.  20.— Left  lacrimal 
bone,  external  surface  (en- 
larged) (Gray). 

moidal  cells 


THE   MALAR   BONES. 


49 


How  is  it  developed? 

From  one  center  in  membrane,  at  the  eighth  fetal  week. 
Tlie  tensor  tarsi  muscle  of  Horner  is  attached  to  it. 

The  Malar  Bones. 

Describe  them. 

Two  small  quadrangular  bones  placed  at  the  upper  outer 
part  of  the  face,  forming  the  prominence  of  the  cheek,  and 
parts  of  the  orbital,  temporal,  and  zygomatic  fossa3.  The  ex- 
ternal surface  (Fig.  21)  is  convex,  smooth,  and  perforated  by 
one  or  more  malar  foramina;  just  below  the  center  the  malar 
tuberositij  gives  origin  to  the  two  zygomatic  muscles.     The  in- 


Busle:  f:jzj3ed  through       /g»'- 
i  tntpoTO' Mular  (h.7iaZs     r^^ 


Fig.  21.— Left  malar  bone,  outer  Fig.  22.-Left  malar  bone,  inner 

surface.  (Gray.)  surface. 

ternal  swface  looks  into  the  temporal  and  zygomatic  fossa  and 
articulates  with  the  superior  maxilla  (Fig.  22).  Superiorly  a 
thick  serrated  fro}ifal  process  articulates  with  the  external  an- 
gular process  of  the  frontal  bone  ;  a  thick,  plate-like  orbital 
process  projecting  backward,  smooth  and  concave  internally, 
forms  part  of  the  floor  and  outer  w\all  of  the  orbit ;  convex 
below,  it  forms  part  of  the  temporal  fossa.  It  bounds  the 
anterior  extremity  of  the  spheno-maxillary  fissure.  Its  upper 
surface  shows  the  orifices  of  one  or  more  temporo-malar  canals 
for  filaments  of  the  orbital  Ijranch  of  the  superior  maxillary 
nerve.  Externally,  projecting  ])ackward  is  the  zygomatic  process^ 
articulating  with  the  zygomatic  process  of  the  temporal  bone 
V^y  a  serrated  margin.  The  maxillari/  process  points  downward 
and  articulates  wnth  the  superior  maxilla. 


50 


ESSENTIALS  OF  HUMAN   ANATOMY. 


The  aiitcro-sHpcrlor  border^  smooth  and  arched,  forms  the 
outer  and  inferior  margin  of  the  orbit ;  the  ((iitenf-infeilor  bor- 
der^ roughly  bevelled,  articulates  with  the  superior  maxilla  ; 
the  poatcro-^iiipcrtor  border^  like  an  italic  /*  is  continuous  above 
with  the  temporal  ridge,  below  with  the  up})er  border  of  the 
zygoma;  the  postero-inferior  b<jider^  thick  and  rough,  gives 
origin  to  the  masseter  muscle. 

How  is  it  developed? 

From  three  centers,  which  unite  at  the  fourth  fetal  month. 
It  articulates  with  the  frontal,  sphenoid,  temporal,  and  superior 
maxillary  bones. 

What  muscles  arise  from  it? 

The  levator  labii  superioris,  zygomaticus  major  and  minor, 
masseter,  and  temporal. 

The  Palate  Bones. 

Describe  them. 

These  two  bones,  situated  at  the   back  part  of  the  nasal 


Ji£/iiTia.  J'ula.ti 


%^      Maa^iila  ry 
Process 


Fig.  23.— Left  palate  bone,  internal  view  (Gray). 

fossae,  assist  in  the  formation  of  the  floor  and  outer  wall  of 
the  nose,  the  roof  of  the  mouth,  the  floor  of  the  orbit,  and  the 
inner  wall  of  the  antrum,  and  aid  in  forming  the  spheno-max- 
illary  and  pterygoid  foss<T  and  the  spheno-maxillary  fissure. 


THE  PALATE  BONES. 


51 


tS^ihenoitlal  /iroeesi. 

ylrtieuUrfrort. 


Of  what  parts  does  each  bone  consist? 

Of  a  vertical  platCi  a  liorizontal  plate^  and  three  processes, 
the  pterygoid.,  .s2)henoidaJ^  and  orhital  (Figs.   !^3  and  24). 

Describe  the  points  on  the  vertical  plate. 

This  thin  oblong  plate,  directed  upward  and  a  little  inward, 
presents  internally  at  its  upper  part  the  superior  turbinated 
crest;  lower,  a  second  ridge,  the 
inferior  turhiuated  crest.,  for  the 
middle  and  inferior  turbinated 
bones,  between  which  lies  the 
groove  for  the  middle  nasal 
meatus ;  below  the  inferior 
crest  is  another  groove.,  for  the 
inferior  meatus.  The  posterior 
harder  articulates  with  the 
pterygoid  process  of  the  sphe- 
noid ;  on  the  external  surface  is 
a  deep  groove  forming  the  pos- 
terior palatine  canal  by  articu- 
lation with  the  superior  max- 
illa, transmitting  the  vessels  and 
nerve  of  the  same  name  ;  the 
upper  and  back  part  of  this  sur- 
face helps  to  form  the  inner 
wall  of  the  spheno-maxillary  fossa.  The  anterior  border  sends 
forward  a  small  lamina  of  bone  opposite  the  inferior  turbi- 
nated crest,  the  tnaxillary  process,  which  narrows  the  orifice 
of  the  antrum.  The  posterior  border  at  the  lower  portion  is 
pyramidal,  forming  the  pterygoid  jrrocess,  which  is  deeply 
grooved,  forming  part  of  the  pterygoid  fossa,  with  a  V-shaped 
rough  margin  for  articulation  with  the  pterygoid  plates. 

The  superior  border.,  deeply  notched  by  the  sphenopalatine 
foramen  (or  notch),  presents  two  processes.  The  orbital  jyrocess 
in  front  articulates  anteriirrly  with  the  maxilla,  posteriorly  with 
the  sphenoid  (its  cells  here  usually  opening  into  the  sphenoidal 
sinus),  internally  with  the  ethmoid,  and  has  a  free  orbital  and 
zygomatic  surface,  the  latter  looking  into  the  zygomatic  fossa, 
with  a  rounded  border  forming  part  of  tlie  spheno-maxillary 
fissure  ;  behind,  projecting  upward  and  inward,  is  the  sphenoidal 
jrroeess,  grooved  on    its   upper   surface    ])y    a   ptery go-palatine 


'""k'. 


Fig.  24.— Left  palate  bone,  posterior 
view  (Gray). 


52  ESSENTIALS  OF  HUMAN   ANATOMY. 

groove  to  help  to  form  the  same-named  canal ;  articulating 
here  with  the  sphenoid  bone  externally  and  posteriorly  with 
the  pterygoid  process,  and  having  an  internal  concave  surface 
forming  part  of  the  outer  wall  of  the  nasal  fossa. 

Describe  the  horizontal  plate. 

This,  completing  the  nasal  floor  and  hard  palate,  presents  on 
its  inferior  surface  a  transverse  rulgc  for  the  tensor  palati  apo- 
neurosis, a  deep  groove  assisting  in  the  formation  of  the  pos- 
terior palatine  canal ;  near  this  the  orifices  of  one  or  two  acces- 
sory posterior  palatine  canals;  an  anterior  border^  serrated 
and  bevelled  for  the  palate  process  of  the  superior  maxilla ;  a 
smooth  concave  posterior  horder  for  the  attachment  of  the 
soft  palate,  terminating  in  the  median  line  by  a  projection, 
which  with  its  fellow  on  the  other  bone  forms  the  posterior 
nasal  spine  for  the  azygos  uvuloe  muscle ;  and  an  internal 
thick  horder^  whose  upper  edge  is  raised  to  form  with  its  fellow 
a  crest  articulating  with  the  vomer. 

How  is  this  bone  developed? 

By  one  center  in  membrane  at  the  angle  of  junction  of  the 
two  plates  (seventh  to  eighth  fetal  weekj. 

With  what  bones  does  it  articulate  ? 

The  sphenoid,  sphenoidal  turbinated,  ethmoid,  superior  max- 
illary, inferior  turbinated,  vomer,  and  opposite  palate. 

Give  the  muscular  attachments. 

Tensor  palati.  azygos  uvulae,  internal  pterygoid,  and  superior 
constrictor  of  the  pharynx. 

The  Inferior  Turbinated  Bones. 

Describe  them  (Figs.  25  and  26). 

They  are  two  thin,  scroll-shaped  bones,  extended  horizon- 
tally along  the  outer  walls  of  the  nasal  fossae,  just  below  the 
orifice  of  the  antrum,  and  are  attached  to  the  inferior  turbi- 
nated crests  of  the  superior  maxillary  and  palate  bones,  and 
present  three  processes  for  study :  a  lacrimal,  in  front  of  the 
upper  border,  forming  part  of  the  lacrimal  canal  by  its  junc- 
tion with  the  lacrimal  and  superior  maxillary  bones  ;  further 
back,  the  ethmoidal  j)Tocess,  joining  the  unciform  process  of  the 
ethmoid  ;  and  from  the  lower  border  of  this  process  the  maxil- 


THE  VOMER. 


63 


lari/  2)rocess  projects,  curving  downward  and  hooking  over  and 
narrowing  the  orifice  of  the  antrum.     The  outer  surface  (from 


KiG.  25.— Riofht  inferior  turbinated  bone,       Fig.  26.— Right  inferior  turbinated 
internal  surface.  (Gray.)        bone,  external  surface. 

the  median  plane  of  the  head)  is  concave ;  its  inner,  convex, 
roughened,  and  grooved  for  arteries  and  veins. 

Name  the  bones  with  which  it  articulates,  and  its  method 
of  development. 

It  articvlatpii  with  the  ethmoid,  hicrimal,  palate,  and  supe- 
rior maxillary  bones  ;  it  is  developed  by  one  center  in  cartilage 
(fifth  fetal  month).     No  muscles  are  attached. 

The  Vomer. 

Describe  it. 

It  is  a  single  bone  shaped  like  a  plowshare,  placed  vertically 
in  the  nasal  fossae  (usually  deviated  to  one  side),  and  forms  part 


ALX 


Fig.  27.— The  vomer  (Gray). 


of  the  nasal  septum.  Its  siiprrior  hordrr  is  deeply  grooved  for 
the  ro.strum  of  the  sphenoid,  with  lateral  loings  (ahx)),  each  of 
which  meets  the  vaginal  process  of  the  pterygoid  process.     The 


54 


ESSENTIALS  OF  HUMAN   ANATOMY. 


anterior  hoixler  is  grooved  for  the  vertical  plate  of  the  ethmoid 
and  the  nasal  septal  cartilage.  The  inffrior  harder  is  received 
in  the  groove  formed  by  the  nasal  crest  of  the  superior  maxil- 
lary and  palate  bones.  The  pnaterior  harder  is  free,  concave, 
thick  above  and  thin  below,  and  separates  the  nasal  fossae  be- 
hind. On  each  lateral  surface  is  the  naso-palatine  groove  (some- 
times a  canal)  for  the  nerve  of  the  same  name,  and  also  small 
furrows  for  the  lodgement  of  blood-vessels. 

Name  the  bones  with  which  it  articulates,  and  its  centers 
of  ossification. 

The  sphenoid,  ethmoid,  both  superior  maxillary,  and  both 
palate  bones.  It  has  two  centers  (eighth  fetal  week  in  mem- 
hrane)^  which  unite  below,  but  form  two  laminae  above  ;  ossifi- 
cation is  not  completed  until  after  puberty.  No  muscles  are 
attached. 

The  Inferior  Maxillary  Bone,  or  Mandible. 

Enumerate  its  general  characteristics. 

It  consists  of  a  hody,  with  two  rami^  which  are  surmounted 
on  either  side  by  a  thin  triangular  coronoid  process  in  front, 


Fig  28.— Inferior  maxillary  bone,  outer  surface,  side  view  (Gray). 

and  an  articular  condyloid  process  posteriorly  ;  the  constricted 
portion  beneath  the  condyle  is  termed  the  neck  of  the  condyle  ; 
the  depression  separating  these  two  processes  is  called  the  sig- 
moid notch,  crossed  by  the  masseteric  vessels  and  nerve. 


THE  INFERIOR   MAXILLARY   BONE. 


55 


Describe  the  body  of  the  bone  (Fig.  28). 

It  is  Iiorseshoe-shaped,  and  presents  a  triangular  eminence 
in  front,  the  mental  jyrocess,  with  a  mental  tnl/erde  on  each  side ; 
extending  upward  is  a  median  vertical  ridge,  the  ayinphyak, 
marking  the  junction  of  the  two  halves  of  the  bone  ;  on  either 
side,  just  below  the  roots  of  the  incisor  teeth,  is  the  incisor 
fossa,  giving  origin  to  the  levator  menti ;  and  more  externally, 
below  the  interval  between  the  two  bicuspid  teeth,  the  mental 
foramen  for  the  exit  of  the  mental  vessels  and  nerve.  Ex- 
tending outward  from  the  base  of  the  mental  process  is  a  dis- 
tinct ridfff.  the  external  oblique  line,  continuous  posteriorly  with 
the  anterior  border  of  the  ramus ;  to  it  are  attached  anteriorly 
the  depressor  labii^nferioris  and  the  depressor  anguli  oris.  The 
lower  border,  just  in  front  of  the  attachment  of  the  masseter, 
is  grooved  for  the  facial  artery.     The  internal  surface  (Fig.  29) 


C£NIO-HVO-CLOSSUS 
CCKIO-HYOIOeuS 


Myh-hycitl  Rid^t 


B  o  dij 
Fig.  29.— Inferior  maxillary  bone,  inner  surface,  side  view  (Gray). 


presents  an  indistinct  linear  depression,  indicating  the  point  of 
junction  of  the  two  halves  of  the  bone,  on  eitlicr  side  of  the 
center  of  which  are  two  prominent  genial  tvhercles,  disposed  in 
pairs,  sometimes  blended  into  two,  or  even  one  irregular  mass, 
the  upper  giving  origin  to  the  genio-hyo-glossi,  the  lower  pair 
to  the  genio-hyoidei  muscles.  Upon  each  side  of  these  tuber- 
cles is  the  oval  stihlingnal  fossa  for  the  gland  similarly  named, 
and   beneath   each  is  a  rough  depression  for  the  origin  of  the 


56  ESSENTIALS  OF  HUMAN  ANATOMY. 

digastric  muscle.  Extending  obliquely  upward  and  backward 
from  the  sublingual  fossa  is  the  internal  ohlique  line  (mylo- 
hyoid ridge)  for  the  same-named  muscle ;  beneath  its  edge  is 
the  oblong  suhmaxillari/  fos.sa  for  the  submaxillary  gland ; 
above  it  is  the  alveolar  portion,  hollowed  into  alveoli  (sockets) 
for  sixteen  teeth  in  the  adult,  ten  in  the  child. 

Describe  the  rami. 

These  ascending,  flattened,  quadrilateral  plates  present  in 
front  the  curved  coronoid  process^  giving  attachment  to  the 
temporal  muscle  by  its  apex,  margins,  and  inner  surface  ;  next 
come  the  sigmoid  notch  and  the  condyle  surmounting  its  nar- 
row neck,  in  front  of  which  is  a  depression  for  the  tendon  of 
the  external  pterygoid  muscle,  and  externarHy  a  small  tubercle 
for  the  external  lateral  ligament.  The  articular  surface  is  ob- 
long, with  its  long  axis  transversely  oblique  from  behind  for- 
ward and  outward,  and  is  convex  from  behind  forward  and 
from  side  to  side.  Upon  the  inner  surface  of  the  coronoid 
process  commences  a  longitudinal  ridge,  with  a  groove,  for  the 
temporal  above,  the  buccinator  muscle  below.  The  outer  sur- 
face of  the  ramus  has  various  ridges  for  the  attachment  of  the 
masseter  muscle  ;  its  inner  surface  presents  a  central  oblique 
aperture,  that  of  the  inferior  dental  canal  (communicating  with 
each  alveolus  and  terminating  at  the  mental  foramen)  for  the 
vessels  and  nerve  ;  in  front  of  this  opening  is  a  prominent  ridge, 
terminating  behind  in  a  sharp  sjyine,  or  lingnla,  for  the  long  in- 
ternal lateral  ligament ;  below  the  spine  is  the  mi/lo-hyoid 
groove  for  the  same-named  vessels  and  nerves  ;  and  behind  the 
groove  is  a  rongli  surface  for  the  internal  pterygoid  muscle. 

At  the  junction  of  the  posterior  and  the  inferior  margins  of 
the  ramus  is  the  angle,  marked  with  rough  oblique  ridges,  ex- 
ternally for  the  masseter,  internally  for  the  internal  pterygoid 
muscle. 

With  what  bones  does  the  inferior  maxillary  articulate? 
With  the  two  temporals. 

What  ossific  centers  has  it? 

It  is  the  second  bone  of  the  skeleton  to  ossify  (clavicle  first), 
and  is  probably  developed  by  several  centers  for  each  lateral 
half,  chiefly  in  menihrane,  partly  in  cartilage,  which  coiissify 
about  the  first  year. 


THE  SUTURES  AND  FONTANELLES.       57 

Compare  the  forms  of  the  old  and  the  adult  jaw. 

Ill  old  age,  the  alveolar  portion  being  absorbed,  the  angle 
formed  by  the  ramus  with  the  body  is  very  obtuse,  and  the 
dental  canal  is  near  the  upper  surface  (important  surgically  m 
operating  for  neuralgia)  ;  in  adult  age  the  ramus  is  almost  ver- 
tical, and  the  dental  canal  lies  about  the  middle  of  the  bone. 

Give  the  muscular  attachments. 

Fifteen  pairs  :  to  each  ramus,  the  masseter,  temporal,  internal 
and  external  pterygoid  ;  to  the  mner  surface  of  the  hody,  the 
genio-hyoglossus,  genio-hyoid,  mylo-hyoid,  digastric,  and  supe- 
rior pharyngeal  constrictor ;  to  the  outer  surface  of  the  body 
the  levator  menti,  depressor  labii  inferioris,  depressor  anguh 
oris,  orbicularis  oris,  platysma  myoides,  and  buccinator. 

The  Sutures  and  Fontanelles. 

What  is  a  suture  ? 

A  line  of  interlocking,  tooth-like  processes,  projecting  from 
the  external  tables  of  Ue  skull  bones  (the  inner  tables  are 
merely  apposed).  Sutures  are  joints  of  the  immovable  class, 
synarthrosis,  and  subclass  syndesmosis,  being  united  by  close 
ligaments.     They  are  nineteen  in  number. 

Name  those  at  the  vertex. 

The  interparietal  (sagittal),  the  fronto-parietal  (coronal),  and 
the  occipito-parietal  (lambdoid). 

Name  those  at  the  sides. 

The   spheno-parietal,  the   squamo-parietal,   and  the  masto- 

parietal. 

Name  those  at  the  base. 

One  basi-sphenoidal,  two  petro-occipital.  two  masto-occipital, 
two  petro-sphenoidal,  and  two  squamo-sphenoidal.  The  points 
of  junction  of  the  sphenoid  with  the  frontal  and  ethmoid,  and 
of  the  frontal  with  the  ethmoid,  are  not  usually  described  as 
sutures. 

Which  only  of  the  facial  sutures  has  received  a  name  ? 

The  traasrerse,  that  extending  from  one  external  angular 
process  of  the  frontal  to  the  other,  joining  that  bone  with  the 


58  ESSENTIALS  OF  HUMAN   ANATOMY. 

malar,   sphenoid,   ethmoid,   lacrimal,   superior  maxillary,   and 
nasal  bones. 

Why  does  the  skull  consist  of  so  many  pieces? 

To  admit  of  continuous  growth  of  the  bones  at  their  edges, 
pari  passu  with  the  growth  of  the  brain  ;  hence  premature  co- 
ossification  of  all  the  sutures  results  in  idiocy.  Obliteration 
of  the  sutures  occurs  at  variable  periods  after  maturity. 

What  are  the  fontanelles? 

They  are  membranous  intervals  in  the  infant's  skull,  corre- 
sponding to  the  junction  of  the  four  angles  of  the  parietal  with 
the  contiguous 'bones.  They  number  six,  viz.,  the  anterior,  of 
lozenge-shape,  at  the  junction  of  the  sagittal  and  coronal  su- 
tures, usually  closed  not  later  than  the  second  year;  the  poste- 
rior ^  triangular,  at  the  junction  of  the  sagittal  and  lambdoid 
sutures,  closed  a  few  months  after  birth  ;  and  the  lateral,  one 
at  the  antero-inferior  angle,  another  at  the  postero-inferior 
angle  of  each  parietal  bone,  which  are  closed  soon  after  birth. 

How  are  these  spaces  closed? 

By  a  gradual  extension  of  the  ossifying  process,  or  by  the 
development  of  additional  centers,  forming  the  so-called 
Wormian  hones. 

THE   SKULL   AS   A   WHOLE. 

The  Cerebral  Fossae. 

Describe  the  general  characteristics  of  the  anterior  fossa  with 
its  foramina  (Fig.  30). 

Formed  by  the  orbital  plates  of  the  frontal,  the  cribriform 
plate  of  the  ethmoid  and  crista  galli,  the  lesser  wings  and  part 
of  the  body  of  the  sphenoid,  it  is  convex  on  either  side  and 
concave  in  the  median  line.  The  foramina  are  one  median, 
the  foramen  csecinn,  which,  if  pervious,  transmits  a  vein  from 
the  superior  longitudinal  sinus  to  the  nose  ;  one  slit  on  each 
side  of  the  crista  galli  for  the  nasal  nerve  ;  three  rows  of  olfac- 
tory foramina  on  each  side  for  the  olfactory  filaments;  on  the 
outer  side  of  each  olfactory  groove  the  anterior  and  the  poste- 
rior ethinoidal  foramina,  the  former  transmitting  the  anterior 
ethmoidal  artery  and  the  nasal  nerve,  the  latter,  the  posterior 
ethmoidal  artery  and  vein. 


THE  CEREBRAL  FOSS.E. 


59 


Groove  pr  Sn^e-r.  tmgituJ.SinKs 
Graavu3  fjr  Aittir  MeninijtalA'' 

Cri^tn  GnMi 
Slit  far  A> m/ 

AnUriMT  JEOimoidalS,/; 

Or  ifiott  far  OlfaeHmj  iieT.f. 
^os^-ctiof  E Jnnaidul  fo 

Ethmoidal  Sj>ins 


Olfactory  CramtJ-— 

Opfi'    Toinmcji- 

Ojiti^  OTOove— 

Olifanj  yraor- 

Ajitnriar  Clirwid  ■pror— 

MiJi/U  Cluwid  jjToe 

PoaterloT  CUnniJ,  j^rroa 

Creovt  for  6'i  7<in-o 

Tor^  Jnctruni  mfdium. 

Cyifiee  of  Ca-ratid  Canal 

Oepttuvtn.    fir  UaSJeriav,  Cavrjlion 


Mcatiii  Auditin-.  Iltternus 

Slit  fjr  I)u.ra-Mafcr 

^up.  Petrosnl   grca-iv 

Fnr.  laeerum  pjiUrius 

Anterior  CotidylcLd Ti^-n 

Aquidu-ct.  Veitibuli 

"PestcrUir  Condyloid  Firr. 


Mastoid  Fai: 
Fast.  MevXnqeal  Groove*. 


I 


\ 


Fig.  30.— Base  of  the  skull,  inner  or  cerebral  surface  (<?ray). 


60  ESSENTIALS  OF  HUMAN   ANATOMY. 

Give  the  boundaries  and  the  foramina  of  the  middle  fossa. 

In  front  it  is  bounded  by  the  posterior  margins  of  the  lesser 
wings  of  the  sphenoid,  the  anterior  clinoid  processes,  and  the 
anterior  margin  of  the  optic  groove  ;  behind,  by  the  upper  bor- 
ders of  the  petrous  portions  of  the  temporal  bones  and  dorsum 
sella) ;  externally  by  the  squamous  plates  of  the  temporals  and 
anterior  inferior  angles  of  the  parietals.  The  foramiria  are  on 
each  side,  the  optic  for  the  optic  nerve  and  the  ophthalmic 
artery.  The  i^plLenoidal  Jissure  transmits  the  third,  fourth,  three 
branches  of  the  ophthahnic  division  of  the  fifth  and  sixth  cranial 
nerves,  and  filaments  of  the  sympathetic,  the  ophthalmic  veins, 
branches  of  the  lacrimal  and  middle  meningeal  arteries  with 
a  process  of  the  dura  mater ;  immediately  behind  this,  the 
foramen  rotundum^  for  the  superior  maxillary  division  of  the 
fifth  cranial  nerve  ;  more  posteriorly,  x\\q  foramen  ovale^  for  the 
inferior  maxillary  division  of  the  fifth  nerve,  the  small  menin- 
geal artery,  and  the  small  petrosal  nerve  ;  between  the  two, 
internally,  the  /oramr/i  Vesalii  (often  absent),  for  a  small  vein  ; 
piercing  the  posterior  inferior  angle  of  the  greater  sphenoidal 
wing,  the  foranwa  spiuoHiim^  for  the  middle  meningeal  artery, 
meningeal  veins,  nervus  spinosus,  a  recurrent  branch  from  the 
inferior  maxillary  nerve,  and  the  sympathetic  branches  from 
the  cavernous  plexus ;  on  the  inner  side  of  the  oval  foramen 
the  foramen  lacernm,  (medium,')  (filled  in  below  by  a  plate  of 
cartilage  in  the  fresh  state),  for  the  internal  carotid  artery, 
carotid  sympathetic  plexus.  Vidian  nerve,  and  a  small  menin- 
geal branch  from  the  ascending  pharyngeal  artery  ;  on  the  an- 
terior surface  of  the  petrous  portion  of  the  temporal  is  seen 
the  eminence  caused  by  the  superior  semicircular  canal,  emi- 
nentia  arcuata  ;  outside  this  the  roof  of  the  middle  ear,  tegmen 
tympani ;  the  groove  leading  to  the  hiafus  Fallopii ;  a  smaller 
groove  and  foramen  for  the  small  superficial  petrosal  nerve  ;  a 
depression  for  the  Gasserian  ganglion  ;  and  the  orifice  of  the 
carotid  canal. 

Describe  the  posterior  fossa. 

It  is  deeply  concave  and  formed  by  the  occipital,  petrous, 
and  mastoid  portions  of  the  temporal,  the  posterior  inferior 
angle  of  the  parietal,  and  part  of  the  body  of  the  sphenoid. 
It  presents  the  meatus  auditorins  internus  for  the  facial  and 
auditory  nerves  and  the  auditory  artery  ;  the  aquaednctus  vesti- 


THE  ORBITAL  CAVITIES.  61 

huli  for  a  small  artery  and  vein ;  the  suhai'cuate  fossa ;  the 
foramen  lacerum  posterius  transmitting  the  glosso-pharyngeal, 
pneumogastric,  and  spinal  accessory  nerves,  the  inferior  petrosal 
and  lateral  sinuses,  and  the  meningeal  branches  of  the  ascend- 
ing pharyngeal  and  occipital  arteries  ;  the  mastoid  foramen,  for 
a  vein  and  artery  ;  i\iQ  posterior  condyloid  foramen  (inconstant) 
for  a  vein ;  the  anterior  condyloid  foramen  for  the  hypoglossal 
nerve,  and  a  meningeal  branch  from  the  ascending  pharyngeal 
artery  :  and  in  the  floor  of  the  fossa  in  the  median  line  is  the 
foramen  magnum,  accommodating  the  medulla  oblongata  and 
membranes,  the  spinal  accessory  nerves,  and  the  vertebral 
arteries. 

What  additional  foramina  or  openings  are  found  at  either 
side  of  the  base  of  the  cranium  (Fig.  31)? 

The  orifice  of  the  Eustachian  tuhe,  admitting  air  to  the  mid- 
dle ear.  The  canal  for  the  tensor  tympani  muscle  above  the 
former,  separated  from  it  by  the  sep>tnm  tubse,  the  posterior 
end  of  which  is  the  processus  cochlear  if  or  mis.  The  posterior 
orifice  of  the  Vidian  canal,  for  the  Vidian  nerve  and  vessels. 
Glaserian  fissure  for  the  processus  gracilis  of  the  malleus, 
and  the  tympanic  branch  of  the  internal  maxillary  artery. 
The  orifice  of  the  caned  of  Huguier,  transmitting  the  chorda 
tympani  nerve.  The  canal  for  Jacohson^s  nerve,  the  tym- 
panic branch  of  the  glosso-pharyngeal.  The  aqusednctvs 
cochlese,  for  a  small  artery  and  vein  running  to  and  from  the 
cochlea.  The  canal  for  Arnold's  nerve,  the  auricular  branch  of 
the  pneumogastric.  The  auricular  fissure,  for  the  exit  of  Ar- 
nold's nerve.  The  stylo-mastoid  foramen,  for  the  exit  of  the 
facial  nerve  and  the  entrance  of  the  stylo-mastoid  artery. 

The  anterior  and  the  posterior  foramina  of  the  palatal  region 
have  already  been  sufficiently  described,  and  this  region  does 
not  properly  belong  to  the  base  of  the  cranium ;  while  those 
opening  (externally  at  the  base  and  upon  the  face  have  been 
d('scrib(!d  sufficiently  under  the  temporal  bone  and  the  supe- 
rior and  inferior  maxillary  bones. 

The  Orbital  Cavities. 

Describe  them  (Figs.  82  and  33). 

Tluey  are  two  (quadrilateral  pyramidal   cavities,  with  bases  ' 
outward,  their  long  axes  directed  from  the  front  inward  and 


62 


ESSENTIALS  OF  HUMAN    ANATOMY. 


Ant  pnlflintfosm 

JTmiismtti  Irfe  Naso-yalat.-n. 
Tmnstiuts Ant  yalat  rcss 
Transmits   right,  NasofalM.t,. 


'fees  sory  palatitia 

Faramina. 

PottNtctiil  Sjiiiir. 
^zvooe   uvuix 

■  Ha  mulit  r  jt  rue 

Vjf/tciioiU.proc.  cf  Palo/te. 
-TltTt/gn-faU,ttne  C. 


TENSOR    PALATI 
■PJuiTi/Tufeal,  Spiru.fvT  ivt.  CONCTDlCa 

-A^utduct.  CoihUa- 
'FoT.  la^etrit.  m.jx>rt*riu  » 
Catuil firrArnolU'l  3h, 


Fig.  31.— Base  of  the  skull,  external  surface  (Gray). 


THE  ORBITAL  CAVITIES. 


63 


backward,  in  such  directions  that  if  prolonged  they  would 
meet  about  the  sella  turcica  of  the  sphenoid.  Seven  bones 
contribute  to  the  formation  of  each,  viz  .  the  frontaP,  the  eth- 


FiG.  32.— Anterior  region  of  the  skull  (Leidj-). 

moid",  the  sphenoid^^,  the  lacrimaP*,  the  superior  maxillary^, 
the  palate'^',  and  the  malar";  each  communicates  with  the 
ciudiial  cavlfij  behind  by  the  optic  foramen  ^^  and  the  sphenoidal 
fissure  ^^,  with  the  nasal  fosna  through  the  canal  of  the  nasal 
duct,  and  below  externally  by  the  spheno-maxillary  fissure '^^ 
with  the  temporal.,  zijgoinatic,  and  sphcno-inaxlUari/  /os.sse. 

What  bones  compose  the  roof,  and  what  is  its  form? 

Tlie  orbital  j)late  of  the  frontal  anteriorly,  the  lesser  sphe- 
noidal wing  behind  ;  it  is  concave  and  directed  downward  and 
forward,  presenting  internally  a  df'pressiou'^**  for  the  fibro-carti- 
laginoiis  pnlh;y  of  tbe  superior  oblicpie  muscle  of  the  eye,  and 
externally  the  lacrunal  Joasa^'  for  the  lacrimal  gland. 


64  ESSENTIALS  OF  HUMAN   ANATOMY. 

Describe  the  floor. 

Nearly  flat,  formed  chiefly  by  the  orbital  plate  of  the  supe- 
rior maxillary'^,  and  to  a  less  extent  by  the  orbital  processes 
of  the  malar ^'^  and  palate  bones;  it  presents  just  external  to 
the  lacrimal  canal  a  depression  for  the  inferior  oblique  muscle  ; 
externally,  the  malo-maxlUary  suture;  near  the  middle,  the 
iiifra-orhital  groove;  and  posteriorly,  the  'palato-maxillary 
suture. 

Name  the  bones  forming,  and  the  points  of  interest  upon  the 
inner  wall. 

It  is  flattened,  formed  by  the  nasal  process  of  the  superior 
maxillary,  the  lacrimal^*,  os  planum  of  the  ethmoid",  and  the 
sphenoidal  body.  It  presents  in  front  the  Jacrhtal  groove''^ ^ 
bounded  behind  by  the  lacrhnal  crest;  further  back  respec- 
tively the  lacrimo-ethmoidal  and  ethmo-sphenoidal  sutures. 

What  forms  the  outer  wall? 

The  orbital  plate  of  the  malar  and  the  greater  wing  of  the 
sphenoid,  and  on  it  are  seen  the  openings  of  one  or  two  malar 
caiiah^^  and  the  s])heno-malar  suture. 

Describe  the  superior  external  angle  of  the  orbit. 

Posteriorly,  the  splienoidal  fissure  (foramen  lacerum  ante- 
rius)^^  for  the  entrance  of  the  third,  fourth,  three  branches  of 
the  ophthalmic  division  of  the  fifth  and  sixth  nerves,  and 
branches  of  the  middle  meningeal  artery,  a  process  of  the  dura 
mater,  sympathetic  nerve  filaments,  and  the  exit  of  the  oph- 
thalmic veins,  and  a  recurrent  branch  from  the  lacrimal  artery. 
This  angle  also  shows  the  fronto-malar  and  the  fronto-splienoi- 
dal  sutures. 

What  points  does  the  superior  internal  angle  present? 

The  suture  between  the  lacrimal,  ethmoid,  and  frontal  bones  ; 
between  the  junction  of  the  two  latter  bones  the  anterior  eth- 
moidal foramen'^  for  the  anterior  ethmoidal  vessels  and  nasal 
nerve,  and  the  j^osterior  ethmoidal  foramen^'  for  the  posterior 
ethmoidal  vessels. 

What  points  does  the  inferior  external  angle  present? 

The  splieno-maxiUari/  Jissure~^  transmitting  the  infra-orbital 
vessels  and  superior  maxillary  nerve,  the  ascending  branches 


THE  ORBITAL   CAVITIES. 


65 


from  the  spheno-palatinc  ganglion,  and  the  orbital  branch  of 
the  superior  maxillary   nerve. 

How  is  the  inferior  internal  angle  formed? 

By  a  HufHif,  the  union  of  the  lacrimal  and  os  planum  of  the 
ethmoid  with  the  superior  maxillary  and  palate  bones. 


TCNDO   OCULt 


Ant.  Ndscd  Sjpine 
Incisi've  fossa 


ii}j^;"y^l,       _y:$^0^^^'^^ arccvePr racial  af 


Fig.  33.— Anterior  region  of  the  skull  (Gray). 

What  foramen  does  the  orbital  margin  present? 

Tlie  siipr(i-(/r/jif(ii^  at  the  junction  ol"  the  inner  and  middle 
thirds,  transmitting  the  supra-orbital  artery,  veins,  and  nerve. 


(j6 


ESSENTIALS  OF  HUMAN   ANATOMY. 


What  foramen  opens  at  the  apex  of  the  orbit? 

The  optlc^''^  between  the  two  roots  of  the  lesser  wing  of  the 
sphenoid,  transmitting  the  optic  nerve  and  the  ophthalmic 
artery. 

Mention  the  nine  openings  communicating  with  the  orbit. 

The  optic'",  sphenoidal  fissure"'  (foramen  laccrum  anterius), 
spheno-maxillary  fissure'^*',  infra-orbital  canal',  anterior^  and 
posterior'^  ethmoidal  foramina,  malar  foramina^",  supra-orbital 
foramen,  and  lacrimal  canal ■■^°  (occasionally,  in  addition,  one  or 
more  external  orbital  foramina  in  the  wing  of  the  sphenoid). 

The  Nasal  Fossae. 

Describe  them. 

They  are  two  irregular  cavities,  extending  from  the  base  of 
the  cranium  above  to  the  roof  of  the  mouth  below,  separated 
in  the  median  line  by  a  thin  osseo-cartilaginous  septum,  open- 

Roof 

NouaZ , 
Jfiual  S^inc  vf  frontal  £one 
BBtaonulFlatc  <rf£t}niwid, 


Prole  poited  thrmLgh 
Nato-lnehiymal  Caiutl 

SrittU  vatstd  through 
IrifundCiaium  ■ 


Fh 

JLnt. Natal  Sjnne 

Palate  /"roc.  of  Suri-Max. 

FalaCo  Broc.  cfFalaU 

foit.  Nasal  Spittt 

Ant.  PalaUiu  CaTUtL 


Oaur  Wall 

''Nasa.k  Broc.  (TfSuptTaX 

i4-^ r-tJ.„vu 

h-1 Vticifoiml^oe  if  Eth. 

Inf<.Ttor  TurbLTia-Udf 
Caiatt 

Sxijarwr  Meatus 
Mi/idU.  Mtatui 
Inferior  Keatut 


Fig.  34.— Roof,  floor,  and  outer  wall  of  the  left  nasal  fossa  (Gray). 


ing  upon  their  facial  aspect  by  two  large  apertures,  the  anterior 
nares,  and  into  the  pharynx  by  the  posterior  nares.  Each  fossa 
communicates  with  four  sinuses  and  four  cavities  (Fig.  34). 


THE  NASAL  FOSSiE.  67 

Of  what  parts  is  the  nasal  septum  composed  ? 

In  front  the  crest  of  the  nasal  bones  and  the  frontal  nasal 
spine ;  its  middle  portion,  the  vertical  plate  of  the  ethmoid  ; 
behind,  the  rostrum  of  the  sphenoid,  the  vomer,  and  the 
sphenoidal  crest ;  below,  the  crests  of  the  superior  maxillary 
and  palate  bones. 

What  points  does  the  roof  of  each  fossa  present  ? 

In  front  the  dit  for  the  nasal  nerve;  wwiwevowfi  foramina  for 
the  olfactory  filaments ;  the  ^pheno-ethmoidal  recess,  and  most 
posteriorly  the  opening  of  the  sphenoidal  sinus. 

The  floor? 

In  front  the  anterior  nasal  sjmie ;  behind  this  the  opening 
of  the  anterior  j^cilatine  canal  and  the  palate  processes  of  the 
superior  maxillary  and  palate  bones ;  internally,  the  nasal  and 
the  incisor  crest;  posteriorly,  the  posterior  nasal  spine. 

Describe  the  chief  points  in  the  outer  wall  of  each  fossa. 

This  presents  three  irregular  longitudinal  passages,  formed 
by  three  projecting  bony  plates,  called  the  siijyerior,  middle, 
and  inferior  meatuses. 

Describe  each  meatus. 

The  superior  occupies  the  posterior  third  of  the  wall,  lies 
between  the  superior  and  middle  turbinated  bones  (processes 
of  the  ethmoid),  and  has  opening  into  it  two  foramina,  the 
sphenopalatine  posteriorly  and  the  posterior  ethmoidal  cells  in 
the  front  part  of  the  upper  wall. 

The  middle  occupies  the  posterior  two-thirds  of  this  wall, 
lies  between  the  middle  and  the  inferior  turbinated  bones,  and 
has  opening  into  it  in  front  the  infnndihidam ;  in  its  center, 
the  antrum,  of  Highmore. 

The  inferior  lies  between  the  inferior  turbinated  bone  and 
the  nasal  floor,  extends  along  the  whole  length  of  the  outer 
wall,  and  has  opening  into  it,  in  front,  the  lower  orifice  of  the 
canal  for  the  nasal  duct  (and  the  anterior  palatine  canal  in  the 
macerated  bone,  not  in  the  natural  state). 

Describe  the  position  and  boundaries  of  the  temporal  fossa. 

Situated   at   the  lateral  region   of  the   skull,  each    fossa  is 


08  ESSENTIALS  OV   HUMAN   ANATOMY. 

marked  out  upon  the  Kkull-cap  by  the  femporal  ridge^  which 
extends  in  a  curved  line  first  upward  and  backward  from  the 
external  angular  process  of  the  frontal  bone,  then  downward 
behind  to  form  the  posterior  root  of  the  zygomatic  process. 
Its  aaterior  boandtuU'n  are  the  frontal,  malar,  and  greater  wing 
of  the  sphenoid  ;  ahoiyi  and  bfJiind^  the  temporal  ridge ;  hdow^ 
the  pterygoid  or  infra-temporal  ridge  on  the  greater  wing  of 
the  sphenoid  ;  (ixtji-imllij.  the  zygomatic  arch  ;  it  opens  below 
into  the  zygomatic  fossa,  is  filled  by  the  temporal  muscle,  and 
is  traversed  by  grooves  for  branches  of  the  deep  temporal 
artery. 

Describe  the  zygomatic  fossa,  its  boundaries  and  communi- 
cating fissures. 

It  is  bounded  anteriorly  by  the  tuberosity  of  the  superior 
maxilla  and  the  ridge  descending  from  its  malar  process ;  hu- 
jferlorhj^  by  the  infra-temporal  ridge  of  the  greater  sphenoidal 
wing  and  under  part  of  the  squamous  plate  of  the  temporal  ; 
behind,  by  the  posterior  border  of  the  pterygoid  process  ;  belov), 
by  the  alveolar  border  of  the  superior  maxilla  ;  iidcrnaJh/,  by 
the  external  pterygoid  plate  ;  and  cxteraallj/.  by  the  ramus  of 
the  lower  jaw  and  the  zygoma.  The  spheno-niaxillary  and  the 
pterijfjo-raaxiUarij  fimiiren  open  into  its  upper  part. 

What  does  it  lodge? 

1'he  internal  and  the  external  pterygoid  and  part  of  the  tem- 
poral muscle,  the  internal  maxillary  artery,  and  the  inferior 
maxillary   nerve,  and  their  branches. 

Describe  the  spheno-maxillary  fissure. 

It  runs  horizontally,  opens  into  the  outer  back  part  of  the 
orbit,  lying  between  the  lower  orbital  border  of  the  greater 
wing  of  the  sphenoid  and  the  outer  border  of  the  orbital  plate 
of  the  superior  maxilla  and  a  small  part  of  the  palate  bone  ; 
externally  is  a  small  part  of  the  malar,  while  internally  it  joins 
the  pterygo-maxillary  fissure  at  a  right  angle  ;  it  transmits  the 
infra-orbital  vessels,  the  superior  maxillary  nerve,  with  its  or- 
bital branch,  ascending  branches  from  Meckel's  ganglion,  and 
serves  to  connect  the  orbit  with  the  spheno-maxillary,  tem- 
poral, and  zygomatic  fossae. 


THE  VERTEBRAL   COLUMN.  69 

What  are  the  boundaries  of  the  ptery go-maxillary  fissure, 
and  what  passes  through  it? 

It  is  bounded  in  front  by  the  maxillary  tuberosity  ;  behind, 
by  the  pterygoid  plate  of  the  sphenoid ;  descends  at  right 
angles  from  the  inner  extremity  of  the  splieno-maxillary  fis- 
sure, transmits  branches  of  the  internal  maxillary  artery,  and 
connects  the  zygomatic  and  the  spheno-maxillary  fossae. 

Describe  the  spheno-maxillary  fossa. 

Situated  at  the  junction  of  the  spheno-maxillary  and  the 
pterygo-maxillary  fissures,  it  is  bounded  ((hove  by  the  under  sur- 
face of  the  body  of  the  sphenoid  ;  in  front  by  the  superior  maxil- 
lary bone  ;  behind,  by  the  pterygoid  process  and  the  lower  part 
of  the  anterior  surface  of  the  great  wing  of  the  sphenoid  ;  inter- 
nally,  by  the  vertical  plate  of  the  palate  with  its  orbital  and 
sphenoidal  processes.  In  this  fossa  terminate  the  i^phenoidal, 
spheno-maxillary,  and  pteri/go-niaxillary  Jissures.  Four  fossae 
communicate  with  it,  the  orbital,  nasal,  zygomatic,  and  the 
middle  cranial  fossae. 

How  many  foramina  open  into  it? 

Five  (sometimes  seven  or  eight)  ;  three  in  the  back  wall, 
viz.  above,  the  foramen  rotnndnm  ;  more  internal  and  inferior, 
theVidian  ;  and  lowest  and  most  internal,  t\\e  ptery  go-palatine  ; 
on  the  inner  wall  is  seen  the  spheno-palatine  foramen  ;  below, 
the  upper  orifice  of  the  posterior  jndatine  canal,  and  sometimes 
two  or  three  accessory  posterior  palatine  canals.  This  fossa  is 
thus  connected  with  three  fissures,  four  cavities,  and  five  fora- 
mina. 

BONES   OF  THE  TRUNK,  AXIAL   SKELETON. 
The  Vertebral  Column. 

How  are  the  vertebrae  divided? 

Into  five  regions,  viz.  cervical  (7)  ;  thoracic  (12)  ;  lumbar  (5) ; 
sacral  (5)  ;  and  coccygeal  (4)  ;  33  in  all. 

What  are  the  sacral  and  coccygeal  vertebrae  called  to  dis- 
tinguish them  from  the  remaining  bones? 

p^ahr  or  fixijd  vertebrae,  the  others  being  called  true  or 
movable  vertebrae. 


70 


ESSENTIALS  OP  HUMAN  ANATOMY. 


What  parts  are  common  to  all  vertebrae? 

A  hody^;  posteriorly  on  each  side  -d  p>didr'\  supporting  two 
lamiiide^,  which,  joining  behind,  form  the  neural  arch  and  en- 


FiG.  35.— A  type-vertebra  (Leidy 


close  the  spinal  foramen^.  The  arch  supports  seven  processes, 
one  spinous^  where  the  laminae  join,  two  transverse'^,  and  four 
articular^. 

Describe  a  vertebral  body. 

It  is  composed  of  cancellous  bone,  with  a  thin,  compact  layer 
externally  ;  its  sides  are  concave  from  above  downward,  while 
its  upper  surface  is  in  the  cervical  region,  concave  laterally, 
forming  a  lip  at  either  side,  while  the  lov:er  surface  is  convex 
from  side  to  side  and  concave  from  before  backward,  forming  an 
anterior  lip  ;  in  the  thoracic  region  it  is  flat  above  and  below  ; 
and  in  the  lumbar  region  flattened,  or  slightly  concave  above 
and  below.  Articular  facets  and  demi-facets  for  the  heads  of 
the  ribs  mark  the  thoracic  bodies,  neither  the  lumbar  nor  the 
cervical  bodies  having  these. 

Describe  the  pedicles. 

They  project  backward  in  all  but  the  cervical  vertebrae,  where 
they  are  directed  obliquely  outward.  They  present  vertehral 
notches  above  and  below  (deepest  ahove  in  the  cervical  verte- 
brae;  heloiD  in  the  thoracic  and  lumbar  spine),  forming,  when 
articulated,  intervertehral  foramina  for  the  exit  of  the  spinal 
nerves  and  the  entrance  of  vessels. 


THE   VERTEBRAL  COLUMN. 


71 


What  are  the  laminae? 

Two  broad  plates  closiiii;  in  the  spinal  foramen,  roughened 


AnteTiorTultTcle  of  Tram.Froc. 

Foramen  f„  Vertebral  ArT  y, 
rattevflrTulcrtU  ofTrant.Proc 


Trantversc  Praeest. 

S^eriirr  Articular  Frarean 
nfenffrArlicularFriictss 


Fig.  36.— Cervical  vertebra  (Gray). 


at  their  upper  margins  and  at  the  inferior  part  of  their  anterior 


surfaces  for  the  ligamenta  subflava. 


Describe  the  transverse  processes. 

They  are  bifid  in  the  cervical  and  perforated  by  the  verte- 
bral foramen  for  the  vertebral  vessels  and  plexus  of  nerves ; 
thick  and  strong,  with  articular  facets  in  the  thoracic  ;  long  and 
slender  in  the  lumbar;  they  spring  from  the  junction  of  the 
pedicle  and  lamina,  and  also  from  the  side  of  the  body  in  the 
cervical  region. 


Describe  the  articular  processes. 

Two  are  superior  and  two  inferior,  projecting  from  the  junc- 
tion of  the  lamina)  and  pedicles.  The  upper  pair  look  h<icl'- 
ward  and  vpicard  in  the  cervical  region  ;  hackirard  and  out- 
inard  in  the  thoracic  ;  Ixickjrard  and  iuicnrd  slightly  in  the 
lumbar;  the  lower  pair  are  exactly  the  reverse  of  the  upper 
in  each  region. 

Describe  the  spinous  processes. 

Kifid,  short,  and  horizontal  in  the  cervical ;  long,  triangular, 
and  din^cted  ((blicpicly  downward  in  the  thoracic;  and  thick, 
broad,   and   (luadrilah^ral   in   tlic;   liinil)ar. 


72  ESSENTIALS  OP  HUMAN  ANATOMY. 

Describe  the  spinal  foramen. 

It  is  largest  and  triangular  in  tlie  cervical,  smallest  and  round 
in  the  thoracic,  medium  and  triangular  in  the  lumbar. 

Name  the  peculiar  vertebrse  of  each  region,  and  describe 
them. 

The  first  cervical,  or  atlas  (Fig.  37)  ;  the  second  cervical,  or 


Traiu.Proct 


Forai7ten  /or 
'ertebral  artery 


GTOoi/efcr  YerceS,  Arty 
ajid  If."  Cerv.N£rii£ 


Spin,  pToc. 

Fig.  37.— First  cervical  vertebra  or  atlas  (Gray). 

axis ;  the  seventh  cervical,  or  vertebra  prominens ;  the  first, 
tenth,  eleventh,  and  twelfth  thoracic,  and  the  fifth  lumbar. 

The  aflaa  supports  the  head,  and  is  formed  of  two  lateral 
masses  joined  by  an  anterior  and  a  jjosterior  arch ;  the  former 


OionUil  Pros, 


Ajrti> 


"j^-ArUe.  Surf foi Atlas 


-i\-Pody 
spin.  I'Toe.. 

1^      T  rant.  Pro 
ZnffT^Tlie.t'roe. 

Fig.  38.— Second  cervical  vertebra  or  axis  (Gray). 

presents  a  facet  posteriorly  for  the   odontoid  process.     Upon 
the  upper  surface  of  each  lateral  mass  is  an  articular  facet 


THE  VERTEBRAL  COLUMN. 


73 


looking  upward,  inward,  and  backward  for  the  occipital  con- 
dyles, while  the  inferior  facet  looks  downward  and  slightly  in- 
ward ;  a  small  tubercle  represents  the  spinous  process.  Devel- 
opment is  by  one  center  for  the  anterior  arch  (first  year)  ;  one 
for  each  lateral  mass  (seventh  fetal  week). 

The  axis  (Fig.  38)  has  surmounting  the  body  the  odontoid 
process^  with  a  facet  in  front  for  articulation  with  the  atlas, 
another  behind  for  the  transverse  ligament,  with  a  roughened  apex 
to  which  are  attached  the  check  ligaments ;  on  each  side  of  the 
odontoid,  facing  upward  and  outward,  are  the  superior  articular 
processes.  Development  is  like 
other  vertebrae,  except  three 
additional  centers  for  the  odon- 
toid, two  appearing  at  the  sixth 
fetal  month,  making  six. 

The  vertebra  jyrominens  (Fig. 
39)  is  so  called  because  of  its 
long  spinous  process,  to  which 
is  attached  the  ligamentum 
nuchae.  Development  is  like 
other  vertebrae,  except  one  ad- 
ditional center  for  the  anterior 
part  of  the  transverse  process. 

Fig.  39.— Seventh  cervical  vertebra, 
The  peculiar  thoracic  vertebrae  or  vertebra  prominens  (Gray). 

(Fig.  41). 

The  first  has  an  entire  facet  and  a  demi-facet  on  the  body  ; 
the  ninth  usually  has  no  peculiarity  ;  the  tenth  has  a  demi- 
facet  on  the  ped'icle  and  one  facet  on  the  transverse  process ; 
the  eleventh  and  twelfth  have  one  facet  on  the  pedicle,  none 
on  the  transverse  processes,  the  latter  also  closely  resembling 
those  of  a  lumbar  vertebra. 

The  fifth  lumbar  has  a  markedly  wedge-shaped  body,  with 
the  base  forward. 

How  are  the  ordinary  vertebrae  developed? 

By  two  centers  for  the  body  and  one  for  each  lamina  (sixth 
to  eighth  fetal  week)  ;  at  sixteen  years  one  center  for  the  tip  of 
each  transverse,  and  two  for  the  spinous  process  ;  and  at  twenty- 
one  years  a  plate  upon  the  upper  and  the  lower  surfaces  of  the 
body,  making  ten  in  all  ;  the  lumbar  vertebriX)  have  two  addi- 


iSsinam  J^LOCfA. 


74 


ESSENTIALS  OF   HUMAN   ANATOMY. 


Dtn'i  facet  for /irai of  Sii 


Sa^rricT  Artie,  troceii  /,'  \ 

DemiJacetforluaA  Cfjiii 


Infer.  Artie  .Proc. 


Fig.  40. — A  thoracic  vertebra  (Gray). 

tional  centers  tipping  the  superior  articular  processes ;  cobssi- 
fication  at  thirty  years. 


{An  entire  facet  above. 
A  demi-facet  below. 


— A  detni-facet  above. 


(An  entire  facet. 
X  No  facet  on  trans,  proc, 
(     ivhich  is  rudimentary. 


(An  entire  facet. 
\  No  facet  on  trans,  proc. 
(Infer,  artic.  proc,  con- 
<      ziex   and  turned  out- 
(^     7vard. 


Fio.  41.— Peculiar  thoracic  vertebrae. 


Describe  the  sacrum. 

It  is  composed  of  five  consolidated  vertebrae,  is  of  triangular 
form  with  broad  base  and  blunted  apex  and  lateral  expanded 


THE   VERTEBRAL  COLUMN. 


75 


masses  or  alas ;    its   anterior  surface  is  concave,  its  posterior 
convex,  and  with  the  coccyx  it  forms  the  posterior  wall  of  the 


Stqjer,  Artie.  Proc 


Fig.  42.— Lumbar  vertebra  (Graj-). 


true  pelvis.     Its  anterior  surface  (Fig.  43)  is  marked  by  four 
transverse  ridges^  indicating  the  lines  of  junction  of  the  seg- 


Tromontorii 


Fig.  43.— .Sacrum,  anterior  surface  (Gray). 

ments ;    ei^rht    (lutpvior   sacral  foramina   with    broad    shallow 
groovf's  for  the   anterior  sacral   nerves   open   on   this   surface; 


76 


ESSENTIAL^  OF  HUMAN  ANATOMY. 


the  point  of  junction  with  the  last  lumbar  vertebra  forms  the 
promontory  (sacro-vertebral  angle)  ;  and  upon  each  side  are 
the  alse — the  expanded  portions  of  the  bone.  Posteriorly 
(Fig.  44)  are  three  or  four  median  tubercles  (rudimentary 
spinous  processes)  ;  externally  are  the  laminae,  those  of  the 
fifth  and  sometimes  the  fourth  being  deficient ;  outside  these 
is  a  row  of  rudimentary  articular  processes;  On  each  side  of 
the  spine  is  a  broad  sacral  groove^  lodging  the  origin  of  the 


upper  half  of  5th 
sacral  foramen 


Fig.  44.— Sacrum,  posterior  surface  (Gray). 


erector  spinae  muscle;  externally  are  the  four j90s/enor  mcral 
foramma  on  each  side  ;  at  the  posterior  inferior  portion  of  the 
bone  are  the  two  cornua — articulating  surfaces  for  the  coccyx  ; 
each  lateral  surface  has  on  its  anterior  upper  part  an  auricular 
surface  for  articulation  with  the  ilium  ;  on  each  side  of  the 
apex  below  is  a  deep  notcli^  for  the  fifth  sacral  nerve;  the  hase 
resembles  the  upper  surface  of  a  lumbar  vertebra,  with  the 
last  of  which  it  articulates ;  the  apex^  directed  downward  and 
forward,  has  an  oval  concave  articular  surface  for  the  coccyx  ; 
the  sacral  canal  runs  the  whole  length  of  the  bone,  triangular 
above,  small  and  flattened  below,  and  deficient  in  its  posterior 


THE   VERTEBRAL  COLUMN.  77 

wall  at  the  lower  part ;  it  lodges  the  sacral  nerves,  and  into  it 
open  the  anterior  and  posterior  sacral  foramina. 

What  centers  of  ossification  has  the  sacrum? 

Thirty-five  or  forty,  appearing  from  the  eighth  fetal  week 
to  the  twentieth  year,  coossification  being  complete  from  the 
twenty-fifth  to  the  thirtieth  year.  The  bodies  have  each 
three  or  four  centers :  each  lamina  one  center ;  the  lateral 
masses  three  centers  each;  the  lateral  surfaces  two  each. 

Give  the  muscular  attachments. 

The  pyriformis,  coccygeus,  and  iliacus  in  front ;  the  gluteus 
maximus,  latissinms  dorsi,  multifidus  spina),  erector  spinas,  and 
sometimes  the  extensor  coccygis  behind — seven  pairs. 

Describe  the  coccyx  (Fig.  45). 

It  is  usually  composed  of  four  rudimentary  vertebrae,  more 
or  less  cobssified ;  it  forms  a  triangular  bone  whose  base^  artic- 
ulates with  the  sacral  apex.  The  first  piece 
presents  two  cornua'^,  projecting  upward  from 
either  side  of  the  base  for  articulation  with 
the  sacral  cornua,  their  junctions  completing 
the  fifth  sacral  foramina  for  the  posterior 
branches  of  the  fifth  nerves.  The  apex^  is 
rounded  and  occasionally  bifid  or  turned  to 
one  side  ;  rudimentary  bodies,  transverse  and 
articular  processes  may  be  seen  on  the  first 
two  segments.  Fig.  45.-Coccyx. 

Describe  its  development. 

From  four  centers :  one  for  each  segment,  the  first  piece 
commencing  at  birth;  second,  five  to  ten  years;  third,  ten  to 
fifteen  years ;  fourth,  fifteen  to  twenty  years ;  coossification 
varies  as  to  time  and  manner. 

Give  the  muscular  attachments. 

Laterally  the  coccygeus;  behind  the  gluteus  maximus  and 
extensor  coccygeus  (inconstant)  ;  apex,  sphincter  ani ;  in  front, 
the  levator  ani. 


78 


ESSENTIALS  OF  HUMAN   ANATOMY. 


The  Hyoid  Bone. 

Describe  this  bone  and  its  development  (Fig.  46). 

It  coii!5it?ts  of  a  body  and  two  yndtcr  and  two  ItHHer  coriiua ; 
the  greater  cor  una  project  backward  from  the  lateral  surfaces 


Thyro-hyoii. 
Slyto-hyoid. 
Oiiw-hyoid. 
-hyoid. 


Gpciio-JiyDid 


Steruo-hyoid. 


Fig.  46. -Hyoid  bone,  anterior  surface  (Gray). 

of  the  body,  and  have  attached  to  their  tubercular  ends  the 
thyro-hyoid  ligaments  ;  the  lesser  cornna,  attached  to  the  junc- 
tion between  the  body  and  the  greater  cornua,  give  attach- 
ment by  their  apices  to  the  stylo-hyoid  ligaments ;  it  is  devel- 
oped  by  five  centers :  one  for  the  body,  one  for  each  greater 
horn  toward  the  end  of  fetal  life,  and  one  for  each  lesser  horn 
some  months  after  birth. 

Give  the  muscular  attachments. 

The  sterno-hyoid,  thyro-hyoid,  omo-hyoid.  digastric,  stylo- 
hyoid, mylo-hyoid,  genio-hyoid,  genio-hyo-glossus.  chondro- 
glossus,  hyo-glossus,  middle  pharyngeal  constrictor,  and  some- 
times the  lingualis. 

The  Thorax. 

Give  its  structure,  form,  and  boundaries. 

It  is  conical  in  form,  and  its  osseo-cartilaginous  framework 
is  formed  by  the  thoracic  vertebral  bodies  behind,  the  ribs  later- 
ally, and  the  costal  cartilages  and  sternum  in  front ;  its  base  is 
formed  by  the  diaphrajim.  Through  its  apex  pass  the  great 
cervical  vessels,  the  pneumogastric,  phrenic,  and  sympathetic 
nerves,  the  trachea,  esophagus,  thoracic  duct,  and  apices  of  the 
lungs  covered  by  pleura. 


THE  STERNUM. 


79 


Fig.  47.— Sternum  and  costal  cartila^'t-s.    Vm.  18.— Posterior  surface  of  sternum. 

(Gray.) 


80  ESSENTIALS  OF  HUMAN   ANATOMY. 

What  are  the  most  important  structures  this  cavity  contains  ? 
The  trachea,  priuiitive  bronchi  and  lungs,  the  heart,  aorta 
and  its  primary  branches,  the  internal  mammary  vessels,  the 
venae  cavae,  bronchial  and  azygos  veins,  the  pneumogastric, 
phrenic,  and  splanchnic  nerves,  the  esophagus,  thoracic  duct, 
lymphatic  vessels  and  glands,  thymus  gland  or  its  remains. 

The  Sternum. 

Describe  it  (Figs.  47  and  48 j. 

The  breast-bone  consists  of  three  segments,  viz.  the  manu- 
brium (handle),  the  gladiolus  (sword),  and  the  ensiform  (xi- 
phoid) cartilage.  Upon  the  upper  border  of  the  manubrium  is 
the  interclavicular  notch,  upon  either  side  of  which  is  the  facet 
for  the  clavicle  ;  lower,  another  for  the  first  rib  ;  below,  a  demi-  - 
facet  for  the  second  rib. 

The  gladiolus  has  a  demifacet  above  for  the  second  rib,  an- 
other below  for  the  seventh  ;  and  between,  facets  for  the  third 
fourth,  fifth,  and  sixth  ribs. 

The  ensiform  cartilage  has  a  demi-facet  above  for  the  carti- 
lage of  the  seventh  rib. 

How  is  this  bone  developed? 

By  six  centers :  one  for  the  manubrium,  four  for  the  gladi- 
olus, one  for  the  ensiform  cartilage  (fifth  fetal  month  to  eigh- 
teenth year)  ;   the  three  pieces  rarely  coossify. 

What  muscles  are  attached  to  this  bone? 

Above,  the  sterno-cleido-mastoid,  the  sterno-hyoid,  and  the 
sterno-thyroid ;  below,  the  rectus  abdominis,  the  external  and 
internal  oblique,  the  transversalis,  and  the  diaphragm  ;  in  front, 
the  pectoralis  major ;  behind,  the  triangularis  sterni. 

The  Ribs. 

What  is  their  number,  and  how  are  they  divided  ? 

Twelve  on  each  side,  seven  of  which  are  true,  or  those  artic- 
ulating with  the  sternum  by  a  separate  cartilage ;  five  false, 
three  of  which  indirectly  articulate  through  the  medium  of  the 
seventh  cartilage ;  while  the  two  lowest,  having  their  anterior 
extremities  free,  are  called  floating  ribs. 


THE   RIBS. 


81 


Of  what  parts  does  a  rib  consist  ? 

A  head,  neck,  shaft,  angle,  and  tuberosity,  except  the  eleventh 
and  twelfth  ribs. 

Describe  these  parts  (Fig.  49). 

The  liead^  (except  the  first,  eleventh,  and  twelfth  ribs,  which 
each  have  only  one  facet)  is  divided  into  two  facets  by  a  ridge 
for  the  interarticular  ligament.  The  neck"-^  is  flattened,  rouyli- 
ened  upon  its  upper  border  for  the  anterior,  and  upon  its  poste- 
rior surface  for  the  middle  costo-transverse  ligaments  ;  in  front 


Fig.  49.—^  and  B,  typical  ribs ;  C,  first  rib ;  D,  twelftli  rib. 

it  is  smooth.  The  tuherosity^  {vih^Qwi  in  the  eleventh  and  twelfth), 
placed  at  the  base  of  the  neck,  presents  a  facet  for  the  trans- 
verse process  of  the  next  lower  vertebra,  and  a  rongh  surface 
for  the  posterior  costo-transverse  ligament.  The  shaft''  is 
twisted  on  its  long  axis  (except  the  first  and  second),  ex- 
ternally convex,  its  upper  border  rounded,  its  lower  grooved^ 
for  the  intercostal  vessels  and  nerve,  and  presents  at  its  ante- 
rior extremity  an  ov(d  depression^'  for  the  costal  cartilage.  The 
angle,  at  a  variable  distance  in  front  of  the  tuberosity,  is  indi- 
cated by  a  rougli  line. 

How  are  the  ribs  developed? 

By  three  centers  (except  the  eleventh  and  twelfth,  two  cen- 
ters), one  each  for  the  head,  shaft,  and  tuberosity  (for  tlie  shaft, 
sixth  fetal  week)  ;  for  the  head  and  tul)erosity  (sixteenth  to 
the  twentieth  year)  ;   cotissifies  at  the  twenty -fifth  year. 

6 


82 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Describe  the  peculiar  ribs. 

Tliey  are  the  first,  second,  eleventh,  and  twelfth  ribs  (Figs.  49 
and  50). 

First  rll)%  broad,  short,  flat,  one  facet  on  the  head,  angle  ab- 
sent ;  on  the  upper  surface  two  parallel  grooves,  the  anterior  for 


<,^'<i^. 


Usually  two  articular  facets 


Single  articular  facet 


Single  articular  facet 


Fig.  50. — Peculiar  ribs. 

the  subclavian  vein,  the  posterior  for  the  artery,  and  between 
them  a  tubercle'^  (Lisfranc's)  for  the  anterior  scalene  muscle,  a 
guide  to  the  suhdavian  artery. 

Second  rih,  also  flattened,  the  tuberosity  and  angle  nearly 
coincide,  and  presents  near  its  middle  a  rough  eminence  for  the 
attachment  of  the  second  and  third  digitations  of  the  serratus 
magnu's  and  for  the  scalenus  posticus. 


THE   PELVIC  BONES.  83 

Tenth  rib,  usually  two  facets  on  the  head,  hence  not  peculiar. 

Eleventh  rib,  one  facet  on  the  head  ;  no  tuberosity,  no  neck, 
slight  angle. 

Ticelfth  rib'^,  one  facet  on  the  head ;  neither  neck,  angle,  nor 
tuberosity. 

Describe  the  costal  cartilages. 

The  costal  cartilages  (Fig.  47)  prolong  the  ribs  to  the  ster- 
num and  greatly  increase  the  elasticity  of  the  chest-wall ;  they 
gain  in  length  to  the  seventh,  and  then  become  shorter ;  their 
breadth  decreases  from  above  down  ;  their  directions  vary  :  the 
first  descends,  the  second  is  horizontal,  the  third  ascends,  and 
the  others  (except  the  last  two)  descend  in  the  line  of  the  rib 
for  a  short  distance  and  then  ascend.  Each  presents  two  sur- 
faces, two  borders,  and  two  extremities  ;  the  anterior  surfaces 
are  convex  and  give  attachment  in  part  to  the  thoracic  and 
abdominal  muscles  ;  the  j^^^sterirjr  surfaces  are  concave,  giving 
attachment  to  the  diaphragm  and  triangularis  sterni ;  the  bor- 
ders give  attachment  to  the  intercostal  muscles  and  fasciae  ;  the 
outer  ends  are  continued  into  the  osseous  tissue  of  the  ribs  ; 
internally,  the  cartilages  of  the  true  ribs  unite  w^ith  the  ster- 
num (see  page  80)  ;  those  of  the  first  three  false  ribs  (eighth, 
ninth,  and  tenth)  become  slender  and  pointed,  and  unite  with 
the  one  above  ;  the  eleventh  and  twelfth  are  pointed  and  free. 
The  sixth,  seventh,  and  eighth  (sometimes  the  fifth  and  ninth) 
have  a  series  of  interchondral  articulations  by  means  of  a 
broad  cartilaginous  band.     All  are  prone  to  ossify  in  old  age. 

The  Pelvic  Bones. 

What  are  they? 

The  ossa  innominata,  the  sacrum,  and  the  coccyx. 

Describe  the  innominate  bone  (Figs.  51  and  52). 

It  is  formed  by  the  union,  about  puberty,  of  three  bones, 
the  ilium,  ischium,  and  pubes  (Fig.  51).  At  their  point  of 
junction  is  the  acetahidum  (cotyloid  cavity)  for  the  head  of 
the  femur — the  pubes  forming  one-sixth,  the  ilium  three-sixths, 
and  the  ischium  two-sixths.  A  rough  central  depression  at  the 
bottom  of  the  acetabulum  lodges  a  vascular  mass  of  fat  covered 
with  synovial  membrane,  while  the  anterior  lower  margin  is  in- 
terrupted  by  the  cotyloid  notch,  bridged  across  by  the  trans- 


84 


ESSENTIALS  OF   HUMAN   ANATOMY. 


verse  ligament,  beneath  which  pass  the  nutrient  vessels  and 
ligament uni  teres,  which  latter  arises  from  either  side  of  the 
notch   externally  ;   the   whole  margin   has   attached  to  it  the 


BCKCLLUS  SUPCRiOR 


SECELCJS   WCERJOS 


Spine  or  Ful,$ 
far  Fnupart's  LlC/tMCDT 


:Tts  AooowyritS 
rrUMiSALis 


Fig.  51. — Right  os  innomiuatum,  external  surface  (Gray). 

cotyloid  ligament.  Between  the  pubes  and  the  ischium,  on  the 
anterior  surface,  is  the  ohfura tor  foramen  (thyroid),  closed  by 
the  membrane  of  the  same  name,  except  above  externally, 
where  the  obturator  vessels  and  nerve  escape ;  the  foramen  is 


THE  PELVIC  BONES.  85 

a  large  ovoidal  opening  in  the  male,  a  smaller  and  triangular 
one  in  the  female. 

Describe  the  ilium. 

This  is  the  upper  expanded  portion  of  the  bone  (Fig.  51), 
presenting  along  its  upper  border  the  crest  with  its  outer 
and  inner  lips,  terminating  in  front  by  the  anterior  superior 
spinovs  process^  giving  origin  to  Poupart's  ligament,  the  sarto- 
rius  and  tensor  fasciae  femoris  muscles,  and  behind  by  the 
posterior  siqyerior  spiuous  process^  to  which  are  attached  part  of 
the  erector  spinae  muscle  and  the  oblique  band  of  the  sacro- 
iliac ligament.  Below  both  the  anterior  and  posterior  spines 
is  a  process  called,  respectively,  the  anterior  (for  the  straight 
tendon  of  the  rectus  femoris  muscle)  and  j^osterior  inferior  spin- 
ous (for  the  great  sacro-sciatic  ligament)  ;  by  these  projections 
a  notch  is  formed  in  front  and  behind,  the  former  giving  partial 
origin  to  the  sartorius  muscle  and  transmitting  the  external 
cutaneous  nerve.  Between  the  posterior  inferior  spine  and  the 
spine  of  the  ischium  is  situated  the  greater  sacro-sciatic  7iofch, 
giving  exit  to  the  pyriformis  muscle,  the  greater  and  lesser 
sciatic,  superior  and  inferior  gluteal  and  pudic  nerves,  also  one 
to  the  obturator  internus  muscle,  and  the  sciatic,  gluteal,  and 
pudic  vessels.  About  two  inches  from  the  posterior  superior 
spine,  passing  downward  and  outward  from  the  crest,  is  the 
svj^erior  gluteal  line,  from  the  surface  back  of  which  arise  the 
gluteus  maximus  muscle  and  a  few  fibers  of  the  pyriformis ; 
about  an  inch  behind  the  anterior  superior  spine,  passing  from 
the  crest  downward  and  backward  to  the  upper  part  of  the 
great  sacro-sciatic  notch,  is  the  middle  gluteal  line,  the  gluteus 
medius  arising  from  the  space  between  these  two  lines  ;  pass- 
ing downward  and  backward,  from  the  upper  part  of  the  ante- 
rior inferior  spine  to  the  front  of  the  sacro-sciatic  notch,  is  the 
inferior  gluteal  line,  between  which  and  the  middle  arises  the 
gluteus  minimus.  Above  the  acetabulum  is  a  groove  for  the 
reflected  tendon  of  the  rectus  femoris  muscle.  The  inner  sur- 
face presents  (Fig.  52)  in  front  the  iliac  fossa  for  the  iliacus 
muscle  and  a  broad  groove  for  the  psoas-iliacus  tendon  ;  pos- 
teriorly is  seen — 1,  a  smooth  surface  below  the  ilio-pectineal 
line  in  the  true  pelvic  cavity  ;  2,  an  auricuhtr  surface  for  the 
sacrum  ;  3,  a  rough  surface  for  the  sacro-iliac  ligaments;  4,  a 
rough  surface  for  the  muscles  of  the  back. 


S6 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Describe  the  ischium. 

It  consists  of  a  hodj/^  fuherosify,  and  ranuis,  and  forms  the 
lowest  part  of  the  innominate  bone.  The  external  surface  of 
the  bod^  forms  two-sixtlis  of  the  acetabulum  ;  below  this  is  a 


f^  \  :  ..■■■■ ^ 


w  ■ 

^'*/*.'   , •' , f  — <>"  (Lt^— * — llio-ischiadic  Junction 


Fig.  52.— Right  os  innominatum,  internal  surface  (Gray). 

groovp  for  the  obturator  externus  tendon  ;  its  inner  surface 
forms  the  lateral  boundary  of  the  true  pelvis  ;  from  the  poste- 
rior border,  below  the  center,  projects  the  f^pine  of  the  ischium^ 
above  and  below  which  are  the  greater  and  lesser  sacro-sciatic 
notches,  the  latter  giving  egress  to  the  obturator  internus  mus- 
cle and  ingress  to  its  nerve  and  to  the  pudic  vessels  and  nerve. 
The  lowest  portion  presents  a  tuberosity^  with  an  outer  and  an 


THE   PELVIC   BONES. 


87 


inner  lip — to  the  latter  being  attached  the  greater  sacro-sciatic 
ligament ;  to  the  outer  is  attached  the  quadratus  femoris  and 
adductor  magnus  muscles.  Passing  upward  and  inward  from 
the  tuberosity  to  join  the  ramus  of  the  pubes,  and  bounding 
the  obturator  foramen  in  front,  is  the  thin,  flattened  ascending 


ramus. 


Describe  the  pubes. 

This  bone  (also  called  pectineal)  consists  of  a  hody^  a  horizon- 
tal and  a  descending  ramus.  The  outer  end  of  the  horizontal 
ramus  forms  one-sixth  of  the  acetabulum  ;  above,  a  rough  dio- 
pcctineal  eminence  indicates  the  point  of  junction  with  the 
ilium  ;  the  inner  end  is  the  oval  symphysis  with  eight  or  nine 
ridges  for  attachment  of  the  fibro-cartilage  ;  the  upper  triangu- 


*^ 

^ 

^ 

* 

4 

^ 

$ 

1^ 

^ 

X 

^ 

Fig.  53.— Plan  of  ihe  (levclopment  of  the  os  innominatum. 

lar  surface  presents  posteriorly  the  pectineal  portion  of  the  ilio- 
pectincid  line ;  the  anterior  surface  presents  the  cres^  ending 
externally  in  the  ]>nhic  spine  giving  attachment  to  Poupart's 
ligament,  internally  in  the  angle;    below  is  a  groove  for  the 


88  ESSENTIALS  OF  HUMAN  ANATOMY. 

obturator  vessels  and  nerve  ;  the  descending  ramus,  thin  and 
flat,  joins  that  of  the  ischium,  completing  the  anterior  bound- 
ary of  the  obturator  foramen. 

How  are  these  bones  developed? 

By  three  primary  centers  (Fig.  53),  one  for  each  bone  (from 
the  eighth  fetal  week)  ;  and  five  secondary  centers  :  one  for  the 
crest,  one  for  the  tuberosity,  one  for  the  anterior  inferior  spine, 
one  for  the  symphysis,  and  one  Y-shaped,  joining  the  three  pieces 
forming  the  acetabulum,  appearing  about  puberty  ;  bone  coos- 
sifies  completely  about  the  twenty-fifth  year.  (For  order  of 
junction,  see  Gray.) 

What  muscular  attachments  has  the  innominate  bone? 

Those  of  the  abdomen,  some  of  the  thigh,  those  of  the  peri- 
neum and  pelvic  floor. 

The  Pelvis. 

Describe  the  pelvis. 

Formed  by  the  two  innominate  bones,  the  sacrum  and  the 
coccyx,  all  above  the  ilio-pectineal  lines  is  called  \\\e  false  pelvis^ 
consisting  of  the  two  iliac  fossst ;  all  below,  the  true  pelvis. 

Describe  the  true  pelvis. 

Its  brim.,  or  inlet,  somewhat  heart-shaped,  is  formed  by  the 
linea  ilio-pectinea  at  the  sides,  completed  in  front  by  the  spine 


Fig.  54.— Diameters  of  the  pelvis. 


and  crest  of  the  pubes,  behind  by  the  anterior  margin  of  the 
base  of  the  sacrum  and  promontory  of  the  sacrum.     Its  aver- 


BONES  OF  THE   UPPER  EXTREMITY.  89 

age  diameters  in  the  female  are,  antero-posterior'^,  four  inches; 
the  oblique"'',  four  and  one-half  inches;  transverse"",  five 
inches  ;  its  long  axis,  if  extended,  would  pass  from  the  middle 
of  the  coccyx  to  the  umbilicus  ;  in  the  male  these  measure- 
ments are  diminished  by  at  least  one-half  inch. 

Describe  the  cavity. 

This  is  bounded  in  front  by  the  symphysis  pubis,  behind  by 
the  concavity  of  the  sacrum  and  coccyx,  on  either  side  by  the 
broad,  smooth  inner  surface  of  the  ischium  and  by  the  lower 
part  of  the  ilium,  forming  a  curved  canal  wider  in  the  middle 
than  at  its  outlets,  measuring  in  depth  of  the  symphysis  one 
and  one-half  inches,  three  and  one-half  inches  in  the  middle 
axial  line,  and  four  and  one-half  inches  posteriorly,  perhaps  as 
much  as  five  and  one-half  inches  in  males. 

Describe  the  lower  circumference  of  the  pelvis. 

This  is  called  the  outlet,  is  bounded  on  each  side  by  the  tu- 
berosity of  the  ischium,  the  pubic  arch  in  front  and  tip  of  the 
coccyx  behind.  Its  diameters,  antero-posterior,  oblique,  and 
transverse,  measure  respectively  five,  four  and  one-half,  and 
four  inches,  being  the  reverse  of  the  diameters  of  the  inlet, 
explaining  the  rotation  of  the  fetal  head  ;  in  the  male  the 
diameters  average  three  and  one-half  inches. 

What  are  the  chief  differences  between  the  male  and  the 
female  pelvis? 

The  strength  of  the  bones,  distinctness  of  the  muscular  im- 
pressions, the  depth  and  narrowness  of  the  cavity,  and  large 
obturator  foramina  mark  the  male  pelvis ;  the  lighter  bones, 
broader  iliac  fossae,  the  less-curved  sacrum,  the  wider  pubic 
arch,  and  the  universally  greater  diameters  distinguish  the 
female  pelvis. 

BONES  OF  THE  UPPER  EXTREMITY. 

Name  the  bones. 

The  clavicle,  scapula,  humerus,  radius,  ulna,  scaphoid,  semi- 
lunar, cuneiform,  pisiform,  trapezium,  trapezoid,  os  magnum, 
unciform,  five  metacarpal,  and  fourteen  phalangeal  bones. 

Describe  the  clavicle. 

It  is  a  long  bone,  curved  like  the  italic  letter/",  its  outer  third 


90 


ESSENTIALS  OF  HUMAN   ANATOMY. 


flattened  from  above  downward,  and  concave  anteriorly  ;  the 
inner  two-thirds  is  cylindrical  and  convex  anteriorly  ;  it  extends 
almost  horizontally  between  the  sternum  and  scapula,  the  two 
extremities  being  respectively  termed  the  sternal  and  the 
acromial. 

Describe  the  chief  points  presented  by  the  clavicle,  com- 
mencing at  the  outer  extremity. 

The  upper  surface  (Fig.  55)  has  impressions^  that  in  front  for 
the  deltoid,  that  behind  for  the  trapezius ;  at  the  outer  end  is 


Sternal  extremity 


Acromial  exircviity 


Fig.  55.— Left  clavicle,  superior  surface  (Gray^i. 

a  facet  articulating  with  the  acromial  process  of  the  scapula ; 
at  the  po.sterior  border,  beneath,  is  the  conoid  tvhercle  (Fig.  56), 


Fig.  56.— Left  clavicle,  inferior  surface  (Gray). 

just  above  the  coracoid  process  of  the  scapula,  for  the  conoid 
ligament ;  extending  from  the  tubercle,  forward  and  outward, 
nearly  to  the  outer  end  of  the  anterior  border  is  the  ohlique 
line  for  the  trapezoid  ligament  ;  occasionally  at  the  center  of 
the  anterior  border  of  the  outer  third  is  the  deltoid  tubercle. 
The  under  surface  of  the  middle  portion  presents  the  subclavian 
groove  for  the  same  named  muscle — either  here  or  on  the  pos- 
terior surface  appears  the  medullar?/  foramen  directed  outward  ; 


BONES  OF  THE  UPPER  EXTKEMITY.       91 

the  inner  third  of  the  superior  border  bears  an  impression  for 
the  sterno-mastoid  muscle  (Fig.  55),  while  the  inner  half  of 
the  anterior  margin  has  another  impression  for  the  pectoralis 
major  muscle.  Beneath  the  posterior  border  of  the  sternal 
end  is  the  rhomboid  impression^  for  the  rhomboid  or  chondro- 
clavicular  ligament.  The  sternal  end  is  triangular  in  form,  its 
inner  surface  for  articulation  with  the  sternum,  this  surface 
being  continuous  with  a  facet  beneath,  for  articulation  with 
the  first  costal  cartilage. 

Give  its  development. 

By  two  centers :  one  for  the  shaft  earliest  in  the  body  Tthirtieth 
day)  ;  one  for  the  sternal  end  (eighteenth  to  twentieth  year) ; 
uniting  about  the  twenty-fifth  year. 

Give  the  muscular  attachments. 

The  sterno-cleido-mastoid,  trapezius,  pectoralis  major,  deltoid, 
subclavius,  sterno-hyoid,  and  usually  the  sterno-thyroid  ;  six  or 
seven  in  all. 

Describe  the  scapula. 

The  shoulder-blade,  a  large,  flat,  triangular  bone,  extends 
from  the  second  to  the  seventh  rib  or  seventh  space  on  the 
back  and  side  of  the  thorax,  its  posterior  margin  lying  nearly 
parallel  to  and  one  inch  from  the  spinous  processes  of  the 
vertebrae. 

The  venter  (anterior  surface)  or  subscapular  fossa  is  concave, 
presents  some  transversely  oblique  ridges  (Fig.  57)  for  the 
tendinous  insertions  of  the  subscapular  muscle,  and  a  mar- 
ginal surface  along  the  inner  border — triangular  above  and 
below,  linear  between — for  the  serratus  magnus  muscle.  The 
suhscapmlar  angle  is  the  transverse  depression  at  its  upper  part 
where  the  fossa  is  deepest. 

The  dorsum  (posterior  surface)  (Fig.  58)  is  divided  by  a 
prominent  bony  ridge,  the  spine^  affording  attachment  to  the 
deltoid  and  trapezius  muscles  and  ending  in  the  acromion 
process,  into  the  supra-  and  inf rasp! nous  f(jssf£,  for  the  origin  of 
similarly  named  muscles;  in  the  latter  is  a  nutrient  foramen. 
The  lower  fossa  presents  a  marrjinal  surface,  divided  by  an 
ohlique  line  at  the  junction  of  the  lower  and  middle  thirds,  into 
two  surfaces,  the  lower  for  the  teres  major,  the  upper   for  the 


92 


ESSENTIALS  OF  HUMAN    ANATOMY. 


teres  minor  muscles ;  about  the  junction  of  the  middle  and 
upper  thirds  of  this  border  is  a  groove  for  the  dorsalis  scapulae 
vessels.  The  spine  internally  presents  a  triangular  surface^ 
over  which  plays  the  ascending  part  of  the  trapezius  muscle. 
The  acromion procesfy  (summit  of  the  shoulder)  is  a  triangular 
flattened  process,  curving  outward,  forward,  and  upward,  to 


Fig.  57.— Left  scapula,  anterior  surfoce  or  venter  (Gray). 

overhang  the  glenoid  fossa ;  giving  attachment  along  its  outer 
margin  to  the  deltoid;  its  inner  margin,  the  trapezius;  by  its 
a/9e.T,  to  the  coraco-acromial  ligament ;  and  having  on  its  inner 
margin,  behind  the  apex,  an  articular  facet  (Fig.  57)  for  the 
clavicle. 


BONES  OF  THE   UPPER   EXTREMITY. 


93 


Describe  the  coracoid  process  of  the  scapula. 

The  coracoid  process  (Figs.  57,  58)  (like  a  crow's  beak)  rises 
by  a  broad  base  from  the  upper  part  of  the  neck  of  the  scapula, 


,p  J* 


Ce  ra  cat'cg   j^ 


Fig.  58.— Left  scapula,  posterior  surface  or  dorsum  (Gray). 

curvinjj^  over  the  inner  part  of  the  glenoid  cavity.  To  the 
anterior  inarfi:;in,  near  tlie  tip,  is  attached  the  p(!ctoralis  minor 
muscle,  and  from  its  apex  arise  the  short  head  of  the  biceps 
and  the  coraco-brachialis  muscle.     To  the  inner  side  of   the 


94  ESSENTIALS  OF  HUMAN   ANATOMY. 

root  is  a  rough  iinpressioii  for  the  conoid  ligament,  whence 
runs  obliquely  forward  and  outward  on  its  upper  surface  a 
ridge  for  the  trapezoid  ligament.  The  coraco-acromial  liga- 
ment is  attached  externally. 

Describe  the  scapular  borders. 

The  superior  border — the  shortest — presents  at  the  base  of 
the  coracoid  the  suprascapular  notch  (Fig.  58),  becoming  a 
foramen  when  the  transverse  ligament  is  in  situ,  through  which 
passes  the  suprascapular  nerve,  above  wdiich  passes  the  supra- 
scapular artery  ;  from  the  border  just  internal  to  the  notch 
arises  the  omo-hyoid  muscle.  The  axillary  border — the 
thickest — presents  just  below  the  glenoid  fossa  a  rough  sur- 
face for  the  long  head  of  the  triceps  muscle,  succeeding  which 
is  a  longitudinal  groove  for  part  of  the  subscapular  muscle. 
The  vertebral  border — the  longest — presents  an  anterior  lip  for 
the  serratus  magnus  muscle,  a  iwsterior  lip  for  the  supra  and 
infraspinatus  muscles,  and  an  interinediate  space  for  the  levator 
scapula)  above,  for  the  rhomboideus  minor  from  the  edge  of 
the  triangular  apex  of  the  spine,  and  for  the  fibrous  arch  of 
the  rhomboideus  major  muscle  below. 

Give  the  points  of  interest  connected  with  the  angles. 

The  superior  angle  (Fig.  57)  affords  partial  attachment  to 
the  serratus  magnus,  to  the  levator  scapulae,  and  supraspi- 
natus  muscles.  The  inferior  angle  (Fig.  58)  affords  attach- 
ment to  the  teres  major  muscle,  part  of  the  serratus  magnus, 
and  (often)  a  few  fibers  of  origin  of  the  latissimus  dorsi.  The 
external  angle,  or  head,  presents  a  shallow  pyriform  glenoid 
fossa  (Fig.  57)  for  the  head  of  the  humerus,  deepened,  in  the 
fresh  state,  by  the  glenoid  ligament,  from  the  upper  part  of 
which  and  from  the  su-praglenoid  tubercle  the  long  head  of  the 
biceps  flexor  cubiti  arises.  The  nech  (Fig.  58)  is  the  slightly 
depressed  surface  surrounding  the  head  ;  the  surgical  neck  is 
well  posterior  to  the  head,  passing  through  the  suprascapular 
notch  (Fig.  58). 

How  is  this  bone  developed? 

By  seven  centers :  one  for  the  body  (second  fetal  month)  ; 
two  for  the  coracoid  (one  at  the  first  year,  one  at  the  fifteenth 
to  the  seventeenth  year)  ;  two  for  the  acromion  ;  one  for  the 
vertebral  border ;   one  for  the   inferior  angle   (all  these    last, 


THE  ARM.  95 

fifteenth  to  seventeenth  year)  ;  coossification  (twenty-second 
to  twenty-fifth  year).  The  acromion  may  not  unite  with  the 
spine  by  bony  union,  but  by  a  gliding  joint  with  synovial 
membrane. 

Give  the  muscular  attachments. 

The  subscapular,  supra  and  infraspinatus,  deltoid,  trapezius, 
omo-hyoid,  serratus  magnus,  levator  scapulae,  rhomboideus 
minor  and  major,  triceps,  teres  minor  and  major,  biceps,  coraco- 
brachialis,  pectoralis  minor,  occasionally  the  latissimus  dorsi. 

The  Arm. 

Describe  the  chief  processes  and  the  general  characteristics 
of  the  humerus. 

This,  the  only  arm  bone,  articulates  above  with  the  scapula, 
below  with  the  ulna  and  radius.  The  upper  extremity,  the  head 
(Fig.  59),  nearly  hemispherical,  facing  upward,  inward,  and 
slightly  backward,  forms  with  the  glenoid  fossa  of  the  scapula 
the  shoulder  or  scapulo-humeral  joint.  Best  marked  supe- 
riorly is  the  constriction  called  the  anatomical  neck,  indi- 
cating the  capsular  attachment ;  external  to  the  head  is  the 
greater  tuherouty,  with  three  facets  for  the  supra-  and  infra- 
spinatus and  the  teres  minor  muscles ;  in  front,  directed 
inward  and  forward,  is  the  lesmr  tiiheroslty  for  the  subscapular 
muscle  ;  commencing  between  these  two  projections,  and 
extending  for  the  upper  third  of  the  bone,  is  the  bicipital 
grooce,  passing  obliquely  downward  and  inward,  lodging  the 
long  head  of  the  biceps  muscle  ;  into  the  anterior  lip  of  this 
groove  is  inserted  the  pectoralis  major  muscle,  into  the  poste- 
rior lip  the  teres  major,  and  into  the  floor  the  latissimus  dorsi. 
The  constriction  beneath  the  tuberosities  is  called  the  sur- 
gical nech.  The  sjiaft,  cylindrical  above,  prismoid  and  flat- 
tened below,  presents  upon  the  middle  of  its  outer  surface  a 
roughness  for  the  deltoid  muscle,  and  below  it,  winding  from 
behind  forward  and  downward,  on  the  back  of  the  bone  ( Fig.  60), 
is  the  spiral  groove  for  the  musculo-spiral  nerve  and  superior  pro- 
funda artery,  internal  and  external  to  which  arise  the  inner  and 
outer  heads  of  the  triceps  muscle.  At  about  the  center  of  the 
inner  bor'ler  of  the  bone  is  an  impression  for  the  coraco-brachialis 
muscle,  just  below  which  is  the  medullury  canal,  directed  down- 
ward.    The  lower  half  of  the  anterior  border,  the  lower  half 


y6 


ESSENTIALS  OF   HUMAN   ANATOMY. 


of  the  external  and  the  internal  sur- 
faces, and  the  internal  supracon 
dylar  ridge  give  origin  to  the  bra- 
chialis  anticus.  The  lower  extremity 
presents  an  iiiatr  (very  proniinent) 
and  an  outer  epicotidyle.,  extending 
from   each   of  which,  upward  on  the 


iurgical  Xt 


luruiiTsi  tuiftt 


>4 


> 


h" 


^. 


/. 


,>\"'  rock  It 


Fig.  59.— Left  humerus,  anterior  Fig.  60.— Left  humerus,  pos- 

view.  (Gray.>  terior  view. 


THE   FOREARM.  97 

shaft,  are  the  internal  and  the  external  supracondylar  rldyes ; 
from  the  external  ridge  and  epicondyle  arise  the  external  lat- 
eral ligament  and  the  extensor  diwH  sujn n afo r  musc\eii  ]  from  the 
inner  epicondyle  and  ridge  arise  the  internal  lateral  ligament  and 
the  flexor  muscles  and  round  pronator.  Projecting  from  the 
lower  front  portion  of  the  outer  condyle  is  the  radial  head 
(capitellum),  for  articulation  with  the  radius  ;  while  internal  to 
this,  extending  from  the  anterior  to  the  posterior  surface  of  the 
hone,  is  the  pulley-like  trod  dear  surface  for  the  greater  sigmoid 
cavity  of  the  ulna.  The  coronoid  fossa  in  front  of  the  trochlea 
receives  the  coronoid  process  of  the  ulna  during  flexion  of  the 
forearm,  while  the  olecranon  fossa,  similarly  placed  behind, 
accommodates  the  tip  of  the  olecranon  during  extension. 

How  is  the  humerus  developed? 

By  seven  centers :  one  for  the  shaft  (fifth  fetal  week)  ;  one 
for  the  head  (first  to  second  year)  ;  one  (sometimes  two;  for 
the  tuberosities  (second  to  third  year  ;  by  the  fifth  year  the  cen- 
ters for  the  head  and  the  tuberosities  have  coossified)  ;  one  for 
the  radial  head  (second  year)  ;  one  for  the  internal  epicondyle 
(fifth  year)  ;  one  for  the  trochlea  (twelfth  year)  ;  one  for  the 
external  epicondyle  (thirteenth  to  fourteenth  year).  The  lower 
centers  are  all  cobssified  with  the  shaft  by  the  sixteenth  or 
seventeenth  year  except  that  for  the  inner  epicondyle,  which 
unites  at  the  eighteenth  year,  while  the  head  unites  at  the  twen- 
tieth year. 

Give  the  muscular  attachments. 

The  supra  and  infraspinatus,  teres  minor,  subscapularis, 
pectoralis  major,  latissimus  dorsi,  teres  major,  deltoid,  coraco- 
brachialis,  brachialis  anticus,  triceps,  subanconeus,  pronator 
teres,  flexor  carpi  ulnaris.  palmaris  longus,  flexor  digitorum 
sublimis,  flexor  carpi  radialis.  supinator  hjngus.  extensor  carpi 
radialis  longior  and  brevior,  extensor  communis  digitorum,  ex- 
tensor carpi  ulnaris,  anconeus,  supinator  brevis,  and  extensor 
minimi  digiti  (sometimes). 

The   Forearm. 

Describe  the  ulna. 

'j'liis,  the  inner  forearm  bone  (Fig.  (51),  longer  than  the 
radius,  forms  the   greater  part  of   the   articulation   vyith    the 

7 


98 


ESSENTIALS  OF  HUMAN   ANATOMY. 


F"»9II    eiCITORUM 
SUBLIMIS 


eeffiriorjj  ortgCn- 
OF  run*  laNcui  poliic 


RaJiaZ  Orurtft 

FLCXOR   DICITORUM 
SUBLIMIS 


Styloid  J'rocna 


urmATOR  LSMOUC 

'OLiieis 
Groove  fur  extensor 
brevi»  poUicia 


StyUcJ  Ifrtent 

Fig.  61.— Bones  of  the  left  forearm,  anterior  surface  (Gray). 


THE  FOREARM.  99 

humerus,  while  it  is  excluded  from  the  wrist-joint  by  the  inter- 
articular  fibro-cartilage.  Its  upper  extremity  forms  the  point 
of  the  elbow.  The  olecranon  process  presents  upon  its  anterior 
part  a  saddle-shaped  articular  surface  which,  with  its  con- 
tinuation on  the  coronoid  process,  is  the  greater  sigmoid  cavity 
for  the  trochlea  of  the  humerus  ;  continuous  with  this  upon 
the  outer  side  is  the  lesser  sigmoid  cavity  for  the  head  of  the 
radius;  to  the  superior  surface  is  attached  the  triceps  tendon, 
and  the  apex  is  accommodated  by  the  olecranon  fossa  of  the 
humerus  during  extension.  Projecting  forward  below  the  ole- 
cranon is  the  coronoid  process,  fitting  into  the  same  named 
fossa  of  the  humerus  during  flexion,  its  upper  surface  forming 
part  of  the  greater  sigmoid  cavity  ;  it  presents,  where  it  joins 
the  shaft,  a  tubercle  for  the  oblique  ligament  and  a  rough  im- 
jwcssion  for  the  brachialis  anticus  muscle  above  and  internally. 
At  the  front  is  a  small  eminence  for  the  flexor  sublimis  digi- 
torum,  whence  descends  a  ridge  for  the  pronator  teres.  The 
shaft,  large  and  prismatic  above,  smaller  and  rounded  below, 
has  on  its  anterior  surface  the  medullary  foramen,  directed 
upward,  and  gives  attachment  to  the  flexor  profundus  digito- 
rum  and  pronator  quadratus  muscles  ;  the  bdernal  surface  gives 
attachment  to  the  flexor  profundus  ;  the  posterior  surface  (Fig. 
62)  gives  attachment  from  above  downward  to  the  anconeus, 
supinator  brevis,  extensor  ossis  metacarpi  pollicis,  extensor 
longus  pollicis,  and  extensor  indicis.  The  jjosterior  border  gives 
attachment  by  a  common  aponeurosis  to  the  flexor  and  exten- 
sor carpi  ulnaris  and  to  the  flexor  profundus  digitorum.  The 
external  sharp  border  aflbrds  attachment  to  the  interosseous 
ligament.  The  lower  carpal  extremity,  or  head,  articulates  by 
its  outer  surface  with  the  sigmoid  cavity  of  the  radius,  and  by 
its  lower  with  the  triangular  fibro-cartilage  ;  projecting  inter- 
nally and  behind  is  the  styloid proces^i,  to  whose  apex  is  attached 
the  internal  lateral  ligament,  to  a  depression  at  its  base  the 
fibro-cartilage  ;  upon  the  posterior  surface  is  a  groove  for  the 
tendon  of  the  extensor  carpi  ulnaris. 

How  is  this  bone  developed? 

By  three  centers  :  one  for  the  shaft  (eighth  fetal  week)  ; 
one  for  the  head  (fourth  year) ;  one  for  the  olecranon  (tenth 
year,  joining  the  shaft  at  the  sixteenth  year)  ;  head  coossified 
with  the  shaft  by  the  twentieth  year. 


100  ESSENTIALS  OF  HUMAN   ANATOMY. 

Give  the  muscular  attachments. 

The  triceps,  anconeus,  flexor  carpi  ulnaris,  brachialis  anticus, 
pronator  teres,  flexor  siiblimis  and  profundus  digitorum,  flexor 
longus  pollicis  (very  often),  pronator  quadratus,  flexor  and  ex- 
tensor carpi  ulnaris,  supinator  brevis,  extensor  ossis  metacarpi 
and  longus  pollicis,  and  extensor  indicis. 

Describe  the  radius. 

Shorter  than  the  ulna,  situated  upon  the  outer  side  of  the 
forearm,  with  a  small  upper  extremity,  forming  only  a  small 
part  of  the  elbow-joint,  its  lower  end  is  large,  forming  the  chief 
part  of  the  wrist-joint.  It  is  slightly  curved  and  of  a  pris- 
matic form.  The  head  (upper  extremity)  (Fig.  61)  is  cylin- 
drical, with  a  slightly  cupped  upper  surface,  articulating  with 
the  radial  head  of  the  humerus,  by  its  side*  with  the  lesser 
sigmoid  cavity  of  the  ulna  and  the  orbicular  ligament  by  which 
it  is  embraced  ;  the  constriction  beneath  the  head  is  the  neck  ; 
below  and  to  the  inner  side  is  the  tvherosiiij.  rough  toward  its 
posterior  margin  for  the  biceps  tendon,  smooth  in  front  for  a 
bursa  ;  the  shaft  is  prismoid,  curved  outward,  smaller  above 
than  below,  having  a  sharp  internal  inferosseons  harder  for  the 
interosseous  ligament,  with  the  med.idlary  foramen  directed 
upward  at  the  junction  of  the  middle  and  upper  thirds  of  the 
anterior  surface.  This  surface  gives  attachment  to  the  flexor 
longus  pollicis  and  pronator  quadratus,  and  by  an  oblique  line 
to  the  radial  head  of  the  flexor  sublimis.  The  external  surface 
gives  attachment  to  the  supinator  brevis  and  pronator  teres. 
The  'posterior  surface  (Fig.  62)  gives  attachment  to  the  supi- 
nator brevis,  extensor  ossis  metacarpi  pollicis,  and  extensor 
brevis  pollicis. 

The  lower  carpal  extremity  has  on  its  lower  face  an  articular 
surface  divided  by  a  slight  ridge  into  two  facets  for  the  semi- 
lunar and  scaphoid  bones ;  upon  its  inner  side  the  shallow 
sigmoid  cavity  for  the  ulnar  head  ;  externally  the  styloid  j^rocess 
giving  attachment  by  its  apex  to  the  external  lateral  ligament, 
by  its  base  to  the  supinator  longus  muscle ;  and  on  its  posterior 
and  external  convex  surfaces  are  five  grooves  for  the  extensor 
tendons. 

How  is  this  bone  developed  ? 

By  three  centers :    one  for  the  shaft  (eighth  fetal  week) : 


THE  FOREARM. 


101 


Ulna 


/./  V,\V    liiiiis  digi- 
tornm. 


For  extensor  carpi  iilnaris. 
'-1-hr  rjttnsor  minimi  digiii. 


For  ezl.  carpi  rod.  longio, . 
Extejisor  carpi  riidi-tli.i  hrevin. . 
Exlf.iisor  lonyus  pollicis. 

Fi<;.  Ci'l. — Ii<jn<'s  of  the  left  foroarin,  postorior  siirfnre 


/  •     /  KxU-naor  ivAicis. 

(  Extensor  communis  digitorum. 


102 


ESSENTIALS  OF  HUMAN   ANATOMY. 


one  for  the  carpal  extremity  (second  year)  ;  and  one  for  the 
head  (fifth  year,  joins  the  shaft  at  puberty)  ;  bone  coossified 
by  about  the  twentieth  year. 

Give  the  muscular  attachments. 

The  biceps,  the  supinator  brevis,  flexor  digitorum  sublimis 
and  longus  pollicis,  pronator  quadratus,  the  extensor  ossis 
metacarpi  and  brevis  polUcis,  pronator  teres,  and  supinator 
longus. 

The   Hand. 

Into  what  segments  is  the  hand  divided  ? 

Into  the  carpus  (eight  bones),  metacarpus  (five  bones),  and 
phalanges  (fourteen  bones)  ;  total,  twenty -seven  bones. 

Describe  the  arrangement  of  the  carpal  bones. 

They  are  placed  in  two  rows  of  four  each  ;  thus,  enumerat- 
ing from  the  radial  to  the  ulnar  side,  with  palm  upward  ;  first, 

or  proximal  row:  scaphoid^,  semi- 
lunar \  cuneiform  °,  pisiform  p;  sec- 
ond, or  distal  row  :  trapezium',  tra- 
pezoidVj  OS  magnum',  unciform**. 

With  how  many  bones  does  each 
articulate  ? 
Scaphoid,  five  ;  semilunar,  five  ; 
cuneiform,  three;  pisiform,  one; 
trapezium,  four;  trapezoid,  four; 
OS  magnum,  seven  ;  unciform,  five. 

Describe  the  chief  peculiarities  of 
each  bone  (Figs.  68,  64,  and 

65). 

The  scaphoid^  (boat-shaped)  has 
on  the  anterior  surface  a  tuberosity  ; 
a  transverse  groove  on  the  dorsum 
parallel  to  the  convex  articular  sur- 
face for  the  radius  ;  facets  for  the  os  magnum  and  semilunar 
bones  on  its  inner  surface  ;  on  its  lower  surface  are  facets  for 
the  trapezium  and  trapezoid. 

The  semihinar^  (half-moon)  presents  a  convex  facet  above 
for  the  radius  and  a  part  of  the  triangular  fibro-cartilage  ;  on 


Fig.  63.— Right   carpal    bones, 
dorsal  surface  (Leidy). 


THE   HAND. 


103 


«,'   «'.t>t»^ 


Carpui 


Metacarpus 


Z^Rovf 


i  r.Rotir 


Fig.  01.— Bones  of  the  left  huinl,  dorsal  surfufe  (tiray). 


its  outer  face  a  semilunar  facet  for  the  scaphoid  ;  on  its  lower, 
a  concave  one  for  the  os  magnum  and  apex  of  the  unciform  ; 
a  (jiiadrilateral  one  on  the  inner  face  for  the  cuneiform. 

Tile  ciuu'jform.^  (wedge-shaped)  has  an  oval  facet  in  front  for 


104  ESSENTIALS  OF  HUMAN  ANATOMY. 

the  pisiform  ;  one  external  for  the  semilunar  ;  an  inferior  con- 
cavo-convex facet  for  the  unciform  ;  a  superior  convex  facet 
f(jr  the  triangular  fibro-cartilage. 

The  pisiform ''  is  rounded,  with  one  ovoida)  facet  for  the 
cuneiform. 

The  trapezium^  is  obliquely  grooved  on  its  palmar  surface 
for  the  tendon  of  the  flexor  carpi  radialis  ;  superiorly  is  a  con- 
cave facet  for  the  scaphoid  ;  below,  a  saddle-shaped  one  for  the 
first  metacarpal :  internally,  one  large  concave  facet  for  the 
trapezoid,  and  a  smaller  one  for  the  second  metacarpal. 

The  trapezrjicV^  is  wedge-shaped,  apex  palmar,  has  four  artic- 
ular surfaces  touching,  separated  by  sharp  edges,  the  external 
for  the  trapezium  ;  inferior  (like  a  ridge-roof),  for  the  second 
metacarpal  ;  internal,  for  the  os  magnum  ;  superior  for  the 
scaphoid. 

The  OS  magnum '  has  superiorly  a  convex  head  for  the  sca- 
phoid and  semilunar,  a  neck  and  body  ;  below,  facets  for  three 
metacarpal  bones  ;  externally,  one  for  the  trapezoid  ;  internally, 
one  for  the  unciform. 

The  unciform''  is  triangular,  has  a  sigmoid  internal  articular 
facet  for  the  cuneiform  ;  two  facets  below  for  the  fourth  and  fifth 
metacarpals  ;  one,  external,  for  the  os  magnum  ;  by  apex  with 
the  semilunar;  from  the  palmar  surface  projects  the  curved 
unciform  process. 

When  do  these  bones  ossify? 

Os  magnum  and  unciform,  during  the  first  year ;  cuneiform, 
third  year ;  trapezium  and  semilunar,  fifth  year ;  scaphoid, 
sixth  year;  trapezoid,  during  the  eighth  year;  pisiform,  about 
the  twelfth  year. 

(The  muscular  attachments  to  the  carpal  and  tarsal  bones 
will  be  given  under  the  Muscular  System.) 

Describe  the  metacarpal  bones. 

They  are  five  long  bones,  with  shaft,  head,  and  base.  The 
first  metacarpal  (sometimes  considered  a  phalanx)  is  shorter, 
has  only  one  facet  on  the  base,  and  has  one  ossific  center  for 
the  shaft  (eighth  fetal  week)  and  one  for  the  haae  (third  year). 
The  second  metacarpal  has  four  facets  on  the  base  for  the  tra- 
pezium, trapezoid,  os  magnum,  and  third  metacarpal;  it,  in 
common   with    the    rest,   has   one    ossific   center  for  the   shaft 


THE   HAND. 


105 


Car  fins 

rLE»OR,CMlFI    Ul." 

FLCXOR    BSEVIS    MlNIMi      OICIT 

FLtHOB    05SIS     METACIRP 
MINIMI      DICITI 


Me.facar/ius 


FLCX 

DREVIS 

& 

ABOU 

CTOB 

RAINIMI 

OICITl 

^ 

<%V 

9 

f^ 

« 

$ 

^    c 

X 

Fig.  65.— Bones  of  the  left  hand,  palmar  surface  (Gray). 

(eighth  fetal  week)  and  one  for  the  head  (third  year ;  they 
coiissify  by  the  twcritictli  year).  The  third  incffirdrjHfJ  articu- 
lates with   tlu'  o.s  iMaixnuiii  ;  on  the  ulnar  side  it  has  two  small 


106  ESSENTIALS  OF  HUMAN   ANATOMY. 

facets  for  the  fourth  metacarpal,  and  a  single  facet  on  the  radial 
side  for  the  second  metacarpal  ;  the  outer  angle  of  its  base  is 
the  styloid  process.  The  fourth  metacarpal  has  two  facets  for 
the  unciform  and  the  os  magnum,  a  single  fjK-et  on  the  ulnar 
side  for  the  fifth  metacarpal,  and  two  small  ones  on  the  radial 
side  for  the  third  metacarpal.  The  Ji/th  metacarpal  articulates 
with  the  unciform  by  a  concavo-convex  facet,  has  only  a  lateral 
facet  on  the  radial  side  for  the  fourth  metacarpal,  and  on  the 
ulnar  side  a  prominent  tubercle  for  the  extensor  carpi  ulnaris 
tendon. 

Describe  the  phalanges. 

They  are  fourteen  in  number — three  for  each  finger,  and  two 
for  the  thumb — they  are  long  bones,  having  a  shaft,  base,  and 
cond3^1es,  except  those  of  the  distal  row.  The  bases  of  the 
first  row.  cup-shaped,  articulate  with  the  heads  of  the  meta- 
carpals ;  those  of  the  second  and  third  have  a  double  concavity, 
separated  by  a  median  ridge,  and  articulate  with  the  condyles 
of  the  row  above  ;  the  distal  extremities  of  the  ungual  phal- 
anges have  rough,  horse-shoe  shaped  tubercles,  ungual  proce.^ses, 
on  their  palmar  surfaces  for  attachment  of  the  pulp  of  the  fin- 
ger ;  they  ossify  by  one  center  for  the  shaft  (eighth  fetal  week), 
and  one  for  the  base  (third  to  fifth  year)  ;  uniting  in  from 
eighteen  to  twenty  years. 

BONES   OF   THE   LOWER   EXTREMITY. 

They  include  those  of  the  hip,  f^'f'ff^i,  ^^ff,  andyoo^ 

The  Thigh. 

Describe  the  femur. 

It  is  the  longest  bone  of  the  skeleton,  and  inclines  toward  its 
fellow  to  bring  the  knee-joint  near  the  center  of  gravity  dur- 
ing walking,  this  obliquity  being  greater  in  the  female,  from 
the  breadth  of  the  pelvis,  and  in  a  short  person  than  in  a  tall 
one  of  either  sex. 

The  head  (Fig.  GO),  forming  rather  more  than  a  hemisphere, 
directed  upward,  inward,  and  forward,  has  behind  and  below  its 
center  the  fossa  capitis  for  the  ligamentum  teres.  The  neck, 
joining  the  head  with  the  shaft,  is  flattened  and  pyramidal  ;  in 
the  adult  male  it  forms  an  obtuse  anirle  with  the  shaft  of  about 


THE  THIGH. 


107 


mvtftr  tenihm 

•1?         »»fL-.Tiy» 


Fig.  06.— Ki^ht  femur,  anterior 
surface. 


Fig.  (17.— Kifcht  femur,  posterior 
(Gray.)  surface. 


108  ESSENTIALS  OF  HUMAN  ANATOMY. 

125°.     After  ossification  is  completed,  twenty  years,  this  angle 
does  not  change  nor  does  the  neck  become  liorizontal. 

The  great  trocJuinter  is  a  large,  irregular,  quadrilateral  emi- 
nence, directed  upward,  outward,  and  backward,  marked  on  its 
external  surface  by  a  diagonal  line  for  the  gluteus  medius  ; 
below  and  behind  this  is  a  smooth  surface  for  a  bursa  beneath 
the  gluteus  maximus  ;  in  front  is  inserted  the  gluteus  minimus  ; 
superiorly  is  the  pyriformis ;  and  upon  its  inner  surface  is  the 
digital  fossa  for  the  tendon  of  the  obturator  externus  muscle  ; 
and  above  that  the  internal  obturator  and  gemelli  muscles  are 
inserted. 

The  lesser  troclianter  (Fig.  67),  small  and  conical,  projects 
from  the  lower  back  part  of  the  base  of  the  neck,  receiving 
the  insertion  of  the  psoas  muscle  above  and  the  iliacus  below. 

The  anterior  B,nd  jxjsterior  intertrochanteric  lines  connect  these 
processes,  the  latter  being  the  more  prominent,  while  to  the 
former  is  attached  the  anterior  portion  of  the  capsular  liga- 
ment. At  the  middle  of  the  posterior  intertrochanteric  line  is 
a  tubercle  for  the  quadratus  femoris  muscle,  sometimes  a  Unea 
qiiadrati. 

The  shaft^  broad  arid  cylindroid  at  either  extremity,  narrow 
and  triangular  in  the  center,  slightly  curved  forward,  has  its 
meduUary  foramen  at  the  junction  of  the  middle  and  lower 
thirds  of  its  posterior  surface,  directed  upward  ;  and  from  its 
anterior  surface  arise  the  crureus  and  subcrureus  muscles. 

The  Unea  aspera,  a  prominent  longitudinal  ridge  occupying 
the  middle  third  of  the  posterior  surface,  has  an  external  and 
an  internal  lip,  and  an  intermediate  space ;  above,  it  divides 
into  three  lines,  one  directed  upward  to  the  base  of  the  greater, 
one  to  the  base  of  the  lesser  trochanter,  a  third,  the  most  inter- 
nal, continuous  with  the  anterior  intertrochanteric  line,  forming 
with  it  the  spiral  line,  while  below  the  linea  aspera  bifurcates 
to  inclose  the  smooth  popliteal  space,  the  inner  division  grooved 
for  the  femoral  vessels.  In  general  terms,  this  line  and  its 
subdivisions  have  attached  the  following  muscles :  the  vastus 
internus  and  externus,  the  pectineus,  the  three  adductors,  the 
short  head  of  the  biceps,  and  the  gluteus  maximus. 

Of  the  two  condf/les,  the  internal  is  the  longer  by  about  half 
an  inch,  to  bring  both  condyles  on  the  same  horizontal  plane 
in  the  normally  oblique  position  of  the  femur;  above  each  con- 
dyle, behind,  is  a  depression  for  the  gastrocnemius  (above  the 


THE   PATELLA.  109 

external  the  plantaris  muscle  also  originates)  ;  separating  them 
is  the  iiitcrconch/loid  notch ^  to  whose  sides  are  attached  the  cru- 
cial ligaments  ;  in  front,  the  condyles  form  a  continuous  artic- 
ular surface,  the  trochlea  ;  the  outer,  as  well  as  the  inner,  con- 
dyle presents  an  epicondyle  upon  its  free  surface  for  the  lateral 
ligaments,  beneath  which,  on  the  outer  condyle,  is  a  groove  for 
the  tendon  of  origin  of  the  popliteus  muscle  ;  above  the  inter- 
nal condyle  is  a  small  adductor  tahercle  for  the  tendon  of  the 
adductor  magnus. 

Give  the  development  of  the  femur. 

By  five  centers :  one  for  the  shaft  (fifth  fetal  week)  ;  one 
for  the  condyles  (ninth  fetal  month)  ;  one  for  the  head  (end 
of  the  first  year)  ;  one  for  the  greater  trochanter  (fourth  year) ; 
one  for  the  lesser  trochanter  (thirteenth  to  fourteenth  year); 
all  coossified  by  the  twentieth  year  in  the  reverse  order  of  their 
appearance. 

Give  the  muscular  attachments. 

The  three  glutei,  pyriformis,  two  obturators,  gemelli, 
quadratus,  psoas,  iliacus,  two  vasti,  short  head  of  biceps,  pecti- 
neus,  three  adductors,  crureus,  subcrureus,  gastrocnemius, 
plantaris,  and  popliteus. 

The  Patella. 

Describe  the  patella  (Fig.  68). 

It  is  flat,  triangular,  placed  at  the  front  of  the  lower  end 
of  the  femur,  and,  being  developed  in  the  quadriceps  tendon, 


11.  h 

Fio.  68.— Right  ijatella  :  a,  anterior  surface  ;  6,  posterior  surface. 

iitf  probably  a  sesamoid  bone  ;  the  convex  anterior  surface  is 
roughened  ;  the  posterior  mrface  is  divided  by  a  vertical  ridge 
into  two  smooth  facets  for  the  trochlea,  the  outer  being  the 


110  ESSENTIALS  OF   HUMAN    ANATOMY. 

broader  and  deeper  ;  the  apex  ^ives  attachment  to  the  liga- 
mentum  patellae ;  and  the  superior  and  lateral  borders  to  the 
rectus  fenioris.  crurcus,  and  vasti  muscles.  It  is  developed  by 
one  center  (about  the  third  year)  ;  the  muscular  attachments 
have  been  already  given. 

The   Leg. 

Describe  the  tibia. 

The  shin-bone,  situated  at  the  inner  front  part  of  the  leg,  is 
only  second  in  length  to  the  femur  ;  the  head^  or  upper  ex- 
tremity, is  large  and  expanded  on  each  side  into  two  lateral 
tuberosities^  bearing  upon  their  upper  surfaces  smooth  concave 
ovoidnl  facets  for  the  femoral  condyles,  between  which  is  the 
vertical,  bifid  spine  for  the  extremities  of  the  semilunar  fibro- 
cartilages,  the  depressions  in  front  and  behind  its  base  giving 
origin  to  the  crucial  ligaments.  Below,  in  the  mid-line,  in 
front  of  the  head,  is  the  tubercle  for  the  ligamentum  patellae 
(Fig.  60)  ;  separating  the  tuberosities  behind  is  the  popliteal 
notch,  giving  attachment  to  the  posterior  crucial  ligament ;  on 
the  posterior  surface  of  the  inner  tuberosity  is  a  transverse 
groove  for  the  insertion  of  the  semimembranosus  tendon  ;  upon 
the  back  of  the  outer  tuberosity,  facing  downward,  is  a  facet 
for  the  head  of  the  fibula ;  running  obliquely  from  this  facet, 
downward  and  inward,  on  the  posterior  surface  (Fig.  70),  is  the 
oblique  line  for  the  popliteal  fascia  and  muscle,  part  of  the  soleus, 
flexor  longus  digitorum,  and  tibialis  posticus  muscles ;  just 
below  the  line,  directed  downward,  is  the  medullary  canal,  the 
largest  in  the  skeleton.  The  external  surface  (Fig.  69)  gives 
attachment  to  the  tibialis  anticus.  The  internal  surface  is 
largely^  subcutaneous  ;  it  gives  attachment  above  to  the  sarto- 
rius,  gracilis,  and  semitendinosus. 

The  prismoid  shaft  has  three  borders,  the  anterior,  called  the 
crest  or  sliin.  and  the  external  or  interosseous  ridge,  for  the  inter- 
osseous membrane,  and  the  internal  for  the  soleus  and  flexor 
longus  digitorum.  The  loioer  extremity,  smaller  than  the  upper, 
has  an  inferior  concave  surface  for  the  astragalus,  an  external 
rough  triangular  surface  for  articulation  with  the  fibula ;  it  is 
grooved  posteriorly  for  the  flexor  longus  hallucis  tendon  ;  has 
projecting  downward  internally  the  internal  malleolus,  which 
articulates  by  its  outer  surface  with  the  side  of  the  astragalus, 
is  grooved  behind  for  the  tibialis  posticus  and  flexor  longus 


THE   LEG. 


Ill 


Bead 


-/^^x 


i-'f'  Jij,' . 


\  V^- !■ 


*  TIBIA 


■UiUUtU^ 


'tt/lmd frttess 


Fig.  69.— Bones  of  the  right  leg,  ante-         Fig.  70.— Bones  of  the  right  leg,  poste- 
rior .surface.  (Gray.)  rior  surface. 

digitorum   tendons,   and   has  attached  to   its   tip  the  internal 
lateral   ligament. 


112  ESSENTIALS  OF  HUMAN   ANATOMY. 

How  is  this  bone  developed? 

By  three  centers  :  one  for  the  shaft  (seventh  fetal  week)  ; 
one  for  the  head  (before  or  at  birth)  ;  one  for  the  lower  end 
(second  year)  ;  bone  coossified  by  the  twenty-first  or  twenty- 
second  year. 

Give  the  muscular  attachments. 

Semimembranosus,  tibialis  anticus  and  posticus,  biceps,  ex- 
tensor and  flexor  longus  digitorum.  sartorius,  gracilis,  semi- 
tendinosus,  popliteus,  soleus,  and  quadriceps  femoris  by  the 
ligamentum  patellae. 

Describe  the  fibula  (peroneal  bone). 

It  is  long,  slender,  and  is  placed  externally  nearly  parallel  to 
the  tibia. 

The  head  or  upper  end  articulates  by  a  flattened  facet  with 
the  external  tibial  tuberosit3\  and  is  prolonged  upward  behind 
into  the  styloid  process  for  the  short  external  lateral  ligament ; 
below  and  behind  is  attached  the  long  external  lateral  liga- 
ment and  the  biceps  tendon. 

The  shafts  triangular  and  twisted  (Figs.  69  and  70),  has 
four  borders  and  four  surfaces  ;  the  borders  are  antero-external, 
antero-interncd  (interosseous),  poster o-external^  and  postero- 
internal;  the  surfaces  are  anterior^  external^  posterior,  and 
internal.  To  the  anterior  surface  are  attached  the  extensor 
longus  hallucis.  extensor  longus  digitorum  and  peroneus  tertius 
muscles  ;  to  the  external  surface,  the  peroneus  brevis  and 
longus ;  to  the  posterior  surface,  the  soleus  and  flexor  longus 
hallucis  ;  to  the  internal  surface,  the  tibialis  posticus.  The 
external  malleolus  forming  the  lower  extremity,  longer  than  the 
internal,  articulates  by  its  inner  surface  with  the  outer  side  of 
the  astragalus  ;  is  grooved  behind  for  the  peroneus  longus  and 
brevis  tendons  ;  to  its  summit  is  attached  the  middle,  and  to 
rough  depressions  in  front  and  behind,  the  anterior  and  poste- 
rior fasciculi  of  the  external  lateral  ligament  of  the  ankle. 

Describe  its  development. 

By  three  centers:  one  for  the  shaft  (eighth  fetal  week); 
one  for  the  malleolus  (second  year)  ;  one  for  the  head  (fourth 
year)  ;  bone  coossified  by  the  twenty-fifth  year,  but,  contrary  to 
ride,  the  lower  epiphysis  unites  frst. 


THE   FOOT. 


113 


Give  the  muscular  attachments. 

Biceps,  soleus,  three  peroneals,  the  extensor  and  flexor  of  the 
great  toe,  the  extensor  longus  digitorum,  and  tibialis  posticus. 

The   Foot. 

Into  what  segments  are  the  bones  of  the  foot  divided? 

Into  the  tarsus  (7)  ;   inetafdrsiis  (5j  ;  and  pkalanyes    (IJ:;  ; 
total,  26  bones  (Figs.  71,  72  and  73). 

Name  the  tarsal  bones. 

Oalcaneum'^  (os  calcis),  astragalus ^  cuboid^,  navicular^,  in- 
ternal, middle **,  and  external'  cuneiform. 

Give  the  chief  peculiarities  of  each  tarsal  bone. 

The  astragalus^  has  a  large  rounded  licad'^  a  neck^  a  hody^^ 
superiorly  a  trochlear  surface  broader  in  front  than  behind,  for 
the  tibia,  and  continuous  with  it  on  either 
^\([q  facets  for  the  internal  and  external  mal- 
leolus ;  the  under  surface  presents  two 
articular  facets,  separated  by  a  groove  for 
the  calcaneo-astragaloid  ligament,  running 
obliquely  forward  and  outward  ;  that  behind 
for  the  calcis,  that  in  front  partly  for  the  cal- 
cis,  but  chiefly  for  the  calcaneo-navicular  liga- 
ment ;  it  articulates  with  the  tibia,  fibula,  os 
calcis.  and  navicular,  and  is  developed  by  one 
center  (seventh  fetal  month). 

The  OS  calcis'^,  tbe  largest  tarsal  bone, 
forms  by  its  tuherositif^  the  heel,  has  a 
groove  on  its  upper  surface  to  correspond  to 
that  of  the  astragalus  ;  behind  and  in  front 
of  which  are  two  articular  facets  for  the 
same  bone  :  on  the  inner  side  projects  the 
sustentaculum  tali  supporting  the  internal 
articular  surface ;  beneath  this  process  the 
innt^r  surface  of  the  bone  is  deeply  concave 
for  the  flexor  tendons,  plantar  vessels,  and 
nerves  ;  its  anterior  c(nicavo-convex  surface 
articulates  with  the  cul>oid  ;  on  the  under 
surface  arc  an  inner  and  an  outer  tuhercle  ; 
it  articulates  with  the  astragalus  and  cuboid,  and  is  dc^'clopcd 


Fk;.  71.— Bones  of 
tlu'  rif^lit  foot,  dorsal 
surface  (Leidy). 


114  ESSENTIALS  OF  HUMAN   ANATOMY. 

from  two  cc'iiter.s,  one  for  the  main  mass  (sixth   fetal  months 
and  one  for  tlie  tuberosity  (tenth  year);   union  alter  puberty. 

The  cuhoiil  lias  one  articular  surface  each  ior  the  os  calcis, 
external  cuneiiorm.  the  fourth  and  fifth  metatarsals,  and  some- 
times lor  the  navicular;  upon  the  under  surface  is  a  deep 
groocc  for  the  peroneus  longus  tendon,  and  behind  this  a  ridge 
terminating  externally  in  a  tubcrosit)/ ;  it  is  developed  from  one 
center  (ninth  fetal  monthj. 

The  navlciihtr^  situated  internally,  is  concave  behind  for  the 
head  of  the  astragalus  ;  is  convex  in  front  with  {\\yq,q  facet s  for 
the  three  cuneiform  bones  ;  externally  there  may  be  di.  facet  for 
the  cuboid ;  and  internally,  below,  is  the  tuberosity  for  part  of 
the  posterior  tibial  tendon  ;  it  is  developed  from  one  center 
(fourth   year). 

The  internal  cuneiform^  the  largest,  is  placed  at  the  inner  side 
of  the  foot,  has  its  base  downward,  upon  which  is  the  tuberosity 
for  partial  insertions  of  the  tibialis  posticus  and  anticus  ten- 
dons ;  in  front  is  a  kidney-shaped y«ct'?  for  the  first  metatarsal ; 
externally  are  two  /r/tr^.s  for  the  second  metatarsal  in  front,  the 
middle  cuneiform  behind  ;  posteriorly  2^  facet  for  the  navicular  ; 
it  is  developed  by  one  center  (third  year). 

.  The  middle  cuneiform,  the  smallest,  has  its  base  upward,  a 
triangular  facet  in  front  for  the  second  metatarsal,  another  be- 
hind for  the  navicular,  along  the  posterior  and  superior  borders 
of  the  inner  face  2l  facet  for  the  internal  cuneiform  ;  and  exter- 
nally a  smooth  facet  for  the  external  cuneiform  ;  it  is  developed 
by  one  center  (fourth  year). 

The  external  cuneiform  is  intermediate  in  size  with  its  base 
upward,  has  an  anterior  triangular  facet  for  the  third  meta- 
tarsal ;  another  posterior  for  the  navicular ;  two  upon  the  in- 
ternal surface  for  the  second  metatarsal  and  middle  cuneiform ; 
and  two  upon  the  outer  surface  for  the  fourth  metatarsal  and 
for  the  cuboid  :   it  is  developed  by  one  center  (first  year). 

Describe  the  metatarsal  bones. 

These  five  long  bones  have  prismoid  shafts^,  anteriorly  a 
head  for  articulation  with  the  phalanges,  posteriorly  a  base 
articulating  with  the  tarsus  and  wnth  one  another. 

The  ///-.s^  metatarsal  \ii,  .shorter,  much  stouter  than  the  others, 
and  articulates  with  the  internal  cuneiform  :   developed  by  one 


THE  FOOT. 


115 


Civot"  /-»  tnJtn  cf 
iLUui  L«ilCS>    HALLUCIS 


Tarsus 


Iniurmca  UaJm  ^ 

2f^t»T  «Rt»H  OrtlTORUMI 


I'Aalanjes 


l«T    igNSuS   HALLUCIS 


Fin.  72.-Bones  of  the  ri>,'ht  foot,  dorsal  surfiicc  (<iray). 


IKJ  ESSENTIALS  OF  HUMAN   ANATOMY. 


ABDUCTOR 


lUienh  of 
A'avicutar 


Two  aeaa- 
moid  bones 


TER     HEAD     OF    ACCESSORY 


FLEXOR     BREVIS    HALLUCIS 


rLcioA  finrvis 

t      JlBOUCTOe 
mHiMl    OICITI 


FLEXOR     LONGU: 
DIGITORUM 


Fig.  73— Bones  of  the  right  foot,  plantar  surface  (Gray). 


THE  ARTICULATIONS.  117 

center  for  the  shaft  (seventh  fetal  weekj  ;  one  for  the  hase 
(third  year),  united  by  the  twentieth  year. 

The  second  metatarsal^  the  longest,  articulates  posteriorly 
with  the  middle  cuneiform,  internally  with  the  internal  cunei- 
form, externally  with  the  external  cuneiform  and  third  meta- 
tarsal, four  bones  in  all :  developed  by  one  center  (seventh  fetal 
week)  for  the  shifty  one  for  the  head  (third  year),  united  at 
twenty  years. 

The  third  metatars<d  has  ^  facet  on  the  base  for  the  external 
cuneiform,  two  on  its  inner  side  and  one  on  its  outer  for  the 
contiguous  metatarsal :  developed  like  the  second. 

The  fourth  me.tatarscd  articulates  behind  with  the  cuboid, 
has  a  facet  on  the  inner  side  divided  into  an  anterior  portion 
for  the  third  metatarsal,  a  posterior  for  the  external  cuneiform, 
and  externally  one  facet  for  the  fifth  metatarsal,  under  which 
is  a  deep  groove  :  developed  like  the  second. 

The  ffth  metatarsid  has  a  triangular  oblique  surface  for  the 
cuboid,  continuous  internally  with  one  for  the  fourth  meta- 
tarsal ;  externally  a  tubercular  eminence :  developed  like  the 
second. 

Describe  the  phalanges. 

They  resemble  closely  those  of  the  hand,  except  that  they 
are  strongly  compressed  from  side  to  side,  instead  of  from  be- 
fore backward :  ossification  also  similar,  but  later.  Thus,  the 
shaft  centers  appear  from  the  second  to  the  fourth  month,  and  the 
epiphyses  appear  at  the  bases  in  the  fourth  to  the  eighth  year. 

THE   ARTICULATIONS. 

How  are  the  articulations  classed? 

In  three  divisions  :  1.  Synarthrosis^  immovable,  as  most  of  the 
cranial  articulations;  2.  I/emiarthrosis,  yielding  (limited  mo- 
tion), as  that  between  the  vertebral  bodies,  or  at  the  pubic 
symphysis ;   8.   Diarfhrosis,  freely  movable. 

Into  what  classes  are  the  synarthroses  divided? 

1.  S//iiehondrosis,  union  by  cartilage,  as  sacro-iliac  joint; 
2.  Sf/ndesmosis,  union  by  ligament,  as  sutures  ;  3.  ^Synostosis, 
union  by  bone,  as  spheno-occipital.     Sutures  are  true  and  false. 

1.    iSnfifra    vera,    including    three    sub-classes — S.    dentata, 


118  ESSENTIALS  OF  HUMAN   ANATOMY. 

tooth-like,  as  the  interparietal  suture ;  S.  sfrrafa,  like  saw 
teeth,  as  the  interfrontal ;  JS.  Umbosa^  when  bevelled  in  addi- 
tion to  dentation,  as  the  fronto-parietal.  The  S.  notlia  (false 
suture)  includes  *S'.  squamosa^  formed  by  two  overlapping  bev- 
elled edges,  as  the  squamo-parietal  suture  ;  and  the  ^S'.  har- 
monia,  mere  apposition  of  roughened  surfaces,  as  the  two  su- 
perior maxillary  bones. 

2.  SchinJj/lesis,  where  a  thin  edge  is  received  into  a  cleft  or 
groove,  as  the  vomer  between  the  superior  maxillary  and  pal- 
ate bones. 

3.  Gompliosis^  the  insertion  of  a  conical  process  into  a  socket, 
as  teeth  in  their  alveoli  (not  really  a  bony  articulation,  as  teeth 
are  not  bones). 

How  are  diarthroses  classed? 

As  arthrodia^  gliding  joints  in  tarsus  and  carpus  ;  enarthroses, 
ball-and-socket  joint — hip-  or  shoulder-joints  ;  ginglymns,  hinge- 
joint — elbow-joint;  frochoides,  or  lateral  ginglymus^  a  pivot 
turning  within  a  ring,  as  the  superior  and  inferior  radio-ulnar 
and  central  atlanto-axial ;  condyloid  where  surfaces  are  ellipti- 
cal, as  radio-carpal  (wrist) ;  reciprocal  reception,  or  saddle- 
shaped  surfaces,  as  first  carpo-metacarpal  (base  of  thumb). 

Motions. — Flexion,  extension,  adduction,  abduction,  circum- 
duction (a  combination  in  succession  of  the  four),  rotation,  and 
gliding. 

What  structures  are  essential  to  the  formation  of  each  of  the 
three  classes  of  articulations? 

For  synarthroses,  two  or  more  bones,  an  interposed  layer  of 
fibrous  tissue  (sutural  ligament)  or,  perhaps,  cartilage  (base  of 
the  skull) ;  syinjyhyses,  an  interposed  bond  of  fibro-cartilage, 
with  strong  bands  of  white  fibrous  tissue,  i.  e.  ligaments  (liga- 
ments are  sometimes  composed  of  yellow  elastic  tissue,  as  the 
ligamenta  subflava  or  ligamentum  nuchae)  ;  diarthroses,  two  or 
more  cartilaginous-coated  surfaces  (reducing  friction),  some- 
times interarticular  fibro-cartilages  to  deepen  joint-surfaces,  as 
those  of  the  knee  and  temporo-maxillary  joints,  a  complete  fi- 
brous capsule,  and  often  additional  ligamentous  bands,  some  in- 
terarticular, i.e.  within  the  joint-cavity,  and  a  synovial  (serous) 
membrane  lining  the  interior  of  the  capsule,  but  not  extending 
upon    the    cartilages ;    a    similar   membrane    also    forms    sacs 


THE  ARTICULATIONS  OF  THE  TRUNK.  119 

(bursae)  outside  the  joints,  with  which  they  often  communi- 
cate, serving  to  reduce  friction  of  the  tendons,  ligaments,  etc.; 
the  layer  of  bone  beneath  the  articular  cartilage  is  the  denser 
articular  lamella;  it  contains  neither  Haversian  canals  nor 
canaliculi,  but  has  larger  lacunae. 

What  is  the  rule  as  regards  the  nerve-supply  of  joints  ? 

The  interior  of  the  joint,  the  muscles  moving  it,  and  the 
skin  over  their  insertions,  are  supplied  by  the  same  trunk  or 
trunks  of  nerves  (this  explains  the  reflex  contractions  of  dis- 
eased joints. 

The  Articulations  of  the  Trunk. 

Describe  the  vertebral  articulations. 

Formed  by  the  contiguous  surfaces  of  the  bodies,  Limin.ie, 
articular,  spinous,  and  transverse  processes  ;  their  ligaments 
are : 

An  iRtervcrtehral  connecting  fihro-cartilage^  or  rZ/'sA:,  between 
the  bodies  of  all  true  vertebrae,  except  the  atlas  and  axis. 

An  anterior  common,  ligament^  passing  medianly  over  the 
fronts  of  the  vertebral  bodies,  most  firmly  attached  to  their 
margins. 

A  posterior  common  ligament^  similarly  disposed  behind  the 
bodies. 

Short  or  lateral  vertehral  ligaments,  fibers  running  at  most 
over  three  vertebrae,  firmly  uniting  the  bodies  where  the  ante- 
rior and  the  posterior  common  ligaments  are  deficient. 

Ligamenta  suhjlava,  of  yellow  elastic  tissue,  connecting  the 
laminae  from  an  internal  surface  above  to  an  upper  edge  below. 

Capsular^,  enclosing  the  articular  processes,  and  lined  with 
.synovial  membrane. 

Supra-  and  inferspinovs,  the  former  connecting  the  tips,  the 
latter  being  interposed  between  the  spinous  processes. 

Intertransverse,  connecting  transverse  processes;  nerves,  spinal 
in  each  region;  arifer/V?.?,  vertebral,  pharyngeal,  and  ascending 
cervical  arteries  in  the  neck,  intercostal  arteries  in  the  thoracic 
region,  and  lumbar  arteries  in  the  loin. 

Describe  the  occipito-atlantal  articulation. 

A    pair    of  ginglijnio-arthrodial  Joints    formed    by    the   con- 


120 


ESSENTIALS  OF  HUMAN   ANATOMY. 


dyles  of  the  occipital  bone  and  the  superior  articular  proc- 
esses of  the  atlas.     Its  ligaments  are : 

Two  anterior  occipito-atlantaP  (Fig.  74),  extending  from  the 
anterior  margin  of  the  foramen  magnum  to  the  anterior  arch 
of  the  atlas,  blending  on  either  side  with  the  capsular  liga- 
ments ;  the  second  ligament  is  a  rounded  cord  in  the  middle 
line. 

A  posterior  occipifo-atlantal,  much  broader,  from  the  poste- 
rior margin  of  the  foramen  magnum  between  the  condyles,  to 
the  postero-superior  border  of  the  posterior  arch  of  the  atlas, 
and  is  incomplete  on  each  side  for  the  ingress  of  the  vertebral 
artery  and  egress  of  the  suboccipital  nerve. 

Two  capsular  ligaments'' ^  lined  with  synovial  membrane,  sur- 
rounding the  articular  surfaces. 

Two  lateral  (or  anterior  ohli<pie^,  passing  upward  and  inward 
from  the  transverse  process  beyond  the  vertebral  foramen  to 
the  jugular  process  of  the  occijjital  bone;  nerve,  suboccipital  ; 
arteries,  from  the  vertebral. 


Describe  the  atlanto-axial  articulation. 

The  lateral  joints  are  arthrodia,  that  between  the  atlas  and 
odontoid   process  is  trochoides.     The   ligaments  of  the  lateral 

joints  and  arches  are  : 

Two  anterior  atlanto-axial*, 
membranous,  passing  between 
the  lower  front  border  of  the 
atlas  to  the  front  of  the  axis 
with  a  central  rounded  cord. 

The    ])osferior    atlaiito-axiid, 

stretching  between  the  postero- 

inferior  edge  of  the  ring  of  the 

.  atlas  to  the  superior  edge  of 

the  arch  of  the  axis  behind  ;  it 

is  pierced  on  each  side  by  the 

second  cervical  nerve. 

The    anterior^'^    common    liii'ament     is    continued    over    the 

median  portions  of  the  above  to  the  occiput,  as  rounded  cords. 

Two    capsidar^^,   synovial-lined,   surrounding    the   articular 

processes. 

The  ligaments  of  the  central  atlanto-axial  joint  are: 

The  transverse'^  (Fig-  75),  extending  between  the  tubercles 


Fro.  74.— Occipito  atlantal   and  at 
lanto-axial  ligaments,  anterior  view 


THE  ARTICULATIONS  OF  THE  TRUNK. 


121 


on  the  inner  surface  of  each  lateral  mass  of  the  atlas ;  it  holds 
the  odontoid  process  in* place,  and  between  the  two  is  a  synovial 
membrane  surrounded  by  a  capsule^  the  transverso-odonfoid 
Joint ;  between  the  odontoid  process  and  the  posterior  surface 
of  the  anterior  arch  of  the  atlas  is  the  atlanto-odontoid  articu- 
lation, surrounded  by  a  aipside  lined  with  synovial  menibrane; 
passing  upward  and  downward  from  the  transverse  ligament 
are  two  bands,  attached  above  to  the  basilar  margin  of  the 
foramen  magnum  ;  below,  to  the  upper  half  of  the  body  of  the 
axis,  forming  a  cross  :  hence  the  transverse  ligament  may  be 
called  the  crucial  ligamerd  ;  nerves^  all  these  joints  are  supplied 
by  the  second  cervical  or  the  loop  between  it  and  the  suboccip- 
ital ;  arteries,  are  branches  of  the  vertebral. 

What  ligaments  connect  the  axis  and  occiput? 

The  posterior  common  ligament^  extends  upward,  to  be 
attached  far  up  the  basilar  process ;  this  ligament  is  usually 
regarded  as 

The  occipito-axial  or  occipito-ccrvical  ligament,  attached 
above  to  the  basilar  groove  of  the  occiput,  below,  to  the  third 


Fig.  73.— Occipito-uxial  and  atlaiito-axiul      Fig.  76.— Temporo-maxillary  artic- 
ligaments,  posterior  view.  illation,  external  view. 


cervical  body  and  that  of  the  axis  (next  comes  the  vertical 
part  of  the  crucial  already  described)  ;  deepest  of  all  are  the 
three  odontoid  ligaments — two  lateral  occipi to-odontoid,  or 
check^,  extending  from  the  sides  of  the  apex  of  the  odontoid 
to  the  inner  edge;  of  the  occipital  condyles,  while  stretching 
between  the  odontoid  tip  and  the  under  surface  of  the  basilar 


122  ESSENTIALS  OF  HUMAN   ANATOMY. 

process,  close  to  the  foramen  magnum,  is  the  central  ocdpito- 
odontoid^  or  ligamentum  svspensoriuni. 

Describe  the  tempore -maxillary  articulation. 

The  upper  compartment  is  (n'throdi(d^  formed  by  the  glenoid 
fossa  and  eminentia  articularis  of  the  temporal  bone  and  the 
upper  surface  of  the  fibro-cartilage ;  the  lower  is  guighjmoid^ 
between  the  under  surface  of  the  fibro-cartilage  and  the  condyle 
of  the  lower  jaw.  The  ligaments  are  capsular^  passing  between 
the  maxillary  and  temporal  bones  near  their  margins,  consisting 
of  ligamentous  fibers,  which  are  thicker  at  certain  parts  and  are 
described  as : 

The  external  lateral  ligament''^  attached  above  to  nearly  the 
whole  length  of  the  lower  edge  of  the  zygoma  and  its  tubercle, 
below  to  the  outer  side  of  the  neck  of  the  condyle  of  the  jaw. 

The  short  internal  lateral  ligament^  extending  between  the 
spine  of  the  sphenoid  and  inner  edge  of  the  glenoid  fossa,  and 
a  ridge  on  the  innqr  side  of  the  neck  of  the  condyle. 

The  long  interned  latercd  ligament  (spheno-mandibular  liga- 
ment), stretching  between  the  spine  of  the  sphenoid  and  the 
forepart  of  the  tip  of  the  inferior  dental  foramen,  the  lingula. 

The  inter eirticular  fibro-cartilage^  concavo-convex  on  the  upper 
surface,  concave  transversely  below,  dividing  the  joint  into  two 
separate  synovial  cavities. 

The  stylo-maxillary  ligament^,  extending  from  the  styloid 
process  to  the  angle  of  the  jaw,  is  really  a  process  of  the  deep 
fascia  ;  nerves^  the  masseteric  and  auriculo-temporal  branches  of 
the  inferior  maxillary  nerve;  etrteries,  temporal,  middle 
meningeal,  ascending  pharyngeal,  posterior  auricular,  tympanic 
branch  of  the  internal  maxillary,  and  ascending  palatine. 

Describe  the  costo-vertebral  articulations. 

These  are  each  formed  (1)  between  the  head  of  a  rib  and  the 
bodies  of  two  adjoining  vertebra?  (except  the  first,  tenth, 
eleventh,  and  twelfth,  which  articulate  with  but  one  vertebra 
e?iQ\i)^hQ\n^ginglymo-art]irrjdifd ;  and  (2)  between  the  tuberosity 
of  each  rib  (except  the  eleventh  and  twelfth)  and  the  trans- 
verse process  of  a  vertebra,  and  is  artJirodial. 

Describe  the  costo-central  articulations. 

The  ligaments  are  : 

A   capsidar  ligament*,  attached    all  around    each    articular 


THE  ARTICULATIONS  OF  THE  TRUNK. 


123 


Fig.  77.  -Costo-vertebral  lig- 
aments, autcrior  view. 


surface,  the  synovial  lining  being  sub- 
divided into  two  cavities  by  the 

Inter<irticul(ir  liganient*,  passing  be- 
tween the  ridge  on  the  head  of  the 
rib  to  the  intervertebral  fibro-carti- 
lage. 

The  stellate  ligament^,  or  anterior 
costo-central,  arising  from  the  ante- 
rior surface  of  the  head  of  the  rib, 
whence  the  fibers  radiate  to  the  ver- 
tebra next  above,  and  below  to  the 
adjoining  vertebra,  and  to  the  inter- 
vertebral disk ;  nerves^  anterior  branches  of  the  spinal  nerves  ; 
arteries,  the  intercostals. 

Describe  the  costo-transverse  articulations. 

Arthrodial,  ten  in  number,  their  ligaments  are : 

Capsular,  attached  beyond  the  margins  of  the  articular  facets. 

Superior  costo-transverse'^  has  two  sets  of  fibers:  the  anterior 
passing  between  the  upper  border  of  the  neck  of  the  rib  to  the 
transverse  process  of  the  vertebra  above ;  the  posterior  to  the 
articular  and  transverse  processes. 

Middle  costo-transverse,  connecting  the  back  of  the  neck  of 
the  rib  with  the  contiguous  transverse  process ;  it  has  three 
parts,  upper  and  lower  and  a  conjugal  ligament  passing  through 
the  spinal  canal. 

Posterior  costo-transverse^  stretching  from  the  tip  of  the  trans- 
verse process  to  a  rough  projection  beyond  the  facet  on  the 
tuberosity  of  the  rib  ;  nerves^  posterior  branches  of  the  thoracic 
nerves ;  arteries,  intercostals  and  posterior  spinal. 

Describe  the  (1)  chondro-sternal  articulations,  i2i  the  con- 
nection between  the  ribs  and  costal  cartilages, 
and  (3)  the  interchondral  joints. 

(1)  The  first,  sixth,  and  seventh  are  synarthrodial,  the  other 
joints  are  arthrodial.  The  first,  sixth,  and  seventh  have  no 
synovial  membrane;  the  third,  fourth,  and  fifth  have  one;  the 
second  has  two.  The  ligaments  are  capsidar ;  the  anterior  and 
posterior  thicker  segments  are  described  as 

Anterior  and  posterior  chondro-sternal  ligaments.  Occasion- 
ally there  is  an  inter  articular  ligament,  notably  in  the  second 
chondroid  joint,  dividing  the  synovial  cavity  into  two. 


124 


ESSENTIALS  OF   HUMAN   ANATOMY. 


(2)  The  coiifal  cartilages  are  firmly  attached  to  the  cup-like 
depression  at  the  end  of  each  rib.  and  by  the  periosteum  con- 
tinued over  to  form  the  perichondrium. 

(3)  The  intercliondral  articulations^  arthrodlal^  are  found 
between  the  edges  of  the  cartilages  of  the  sixth,  seventh,  and 
eighth  ribs,  sometimes  the  fifth  and  ninth,  having  each  a  cajiside 
lined  with  synovial  membrane.  In  addition  there  is  an  anterior 
and  a  posterior  cltondro-xiplioid  ligament  which  binds  the 
xiphoid  cartilage  and  the  sixth  and  seventh  cartilages  together  ; 
nerves^  intercostals ;  arteries^  internal  mammary  or  its  branches. 

Describe  the  ligaments  of  the  sternum. 

The  njanubrium  and  gladiolus  are  bound  together  by  the 
anterior  and  posterior  intersternal  ligaments,  with  a  layer  of 
cartilage  between  them  (an  ampliiarthrodial  joint ^  sometimes 
a  diarthrrjdial)  ;  that  between  the  ensiform  cartilage  and  the 
gladiolus  is  synarthrodial. 

Describe  the  sacro-vertebral  articulation. 

Similar  to  other  vertebral  articulations,  but  has,  in  addition, 
The   sacrodumhar  ligament,  extending  from  the   transverse 

process,  pedicle,  and  body  of  the  fifth  lumbar  vertebra  to  the 

non-articular  portion  of  the  base  of 
the  sacrum  and  periosteum  of  the  ilium, 
and  anterior  sacro-iliac  ligament. 

The  iliodnmhar  ligament^  (Fig.  78), 
extending  from  the  front  surface  and 
tip  of  the  transverse  process  of  the 
fifth,  and  lower  edge  and  front  sur- 
face of  the  transverse  process  and 
pedicle  of  the  fourth  lumbar  verte- 
bra, to  the  inner  lip  of  the  iliac  crest; 
nerves,  fourth  and  fifth  lumbar,  sympa- 
thetic ;  arteries,  ilio-lumbar,  last  lum- 
bar, and  lateral  sacral. 


Describe  the  sacro-iliac  articulations. 

They  are  synarthrodial,  formed  be- 
tween the  auricular  surfaces  of  the 
ilium  and  sacrum,  and  have  the  fol- 
lowing ligaments  upon  each  side,  in  addition  to  the  symphy- 
seal  cartilage : 


Fig.  T8.— Ligaments  of  pelvis 
and  hip,  posterior  view. 


THE   ARTICULATIONS   OF   THE  TRUNK.  125 

The  anterior  sacro-iliac^  (Fig-  81),  from  the  three  first  pieces 
of  the  sacrum  to  the  ilium  on  their  pelvic  surfaces. 

The  poster  lor  sacro-lUac'^  (Fig.  78),  very  strong,  extending 
between  the  back  of  the  sacrum  and  the  posterior  two  inches 
of  the  iliac  crest,  including  the  posterior  superior  iliac  spine. 

An  otjUtpie  Ugrimeiit^  stretching  between  the  third  articular 
tubercle  of  the  sacrum  to  the  po.sterior  superior  iliac  spine. 

Superior  and  inferior  bands  of  fibrous  tissue  closing  in  the 
joint  above  and  below,  belong  to  the  anterior  sacro-iliac. 

The  interosseous  ligament^  strongest  of  all,  consists  of  numer- 
ous ligamentous  bands  passing  between  the  contiguous  rough 
surfaces  of  the  sacrum  and  ilium  ;  nerves^  from  the  superior 
gluteal,  posterior  sacral,  and  lumbo-sacral  cords;  arteries,  t\iQ 
gluteal,  ilio-lumbar,  and  lateral  sacral. 

Describe  the  ligaments  connecting  the  sacrum  and  ischiatic 
bones  on  each  side. 

They  are  the  : 

Greater  sacro-sciatic^,  thin,  triangular,  passing  from  the  pos- 
terior inferior  iliac  spine,  fourth  and  fifth  articular  sacral  tu- 
bercles and  lower  lateral  margin  of  the  sacrum ,  and  from  the 
coccyx  to  the  inner  margin  of  the  ischiatic  tuberosity,  forming 
here  the  falciform  process. 

The  lesser  sacra-sciatic*,  anterior  to  the  former,  of  same  shape, 
stretching  between  the  lateral  margins  of  the  sacrum  and 
coccyx  and  the  spine  of  the  ischium.  It  is  blended  with 
the  coccygeus  muscle. 

These  ligaments  convert  the  two  sacro-sciatic  notches  into 
the  greater  (by  lesser  ligament)  and  the  lesser  (by  greater 
ligament)  sacro-sciatic  foramina,  described  under  the  iliac  and 
ischiatic  bones. 

Describe  the  sacro-coccygeal  articulation. 

AnrjtliiartlirodiaL  its  ligaments  are  : 

An  inter  articular  fihro-cartilage,  like  that  between  vcrtebn\}. 

An  anterior  sacro-coccygeal,  a  continuation  of  the  anterior 
common  vertebral. 

A  posterior  sacro-coccygeal,  a  continuation  of  the  posterior 
common,  of  the  supraspinous  and  intcrspinous  ligaments  and 
the  filum  terminal''. 

IritprconiiKil  ;ind   intertransverse  bands,  connecting  jiarts  of 


120  ESSENTIALS  OF  HUMAN   ANATOMY. 

the  same  name  ;  nerves,  anterior  and  posterior  branches  of  the 
fifth  sacral  and  coccygeal,  posterior  division  of  the  fourth,  and 
probably  the  second  and  third  sacral ;  arteries,  lateral  and 
median  sacral. 

Describe  the  pubic  articulation. 

Ampliuirthrudial,  between  the  two  pubic  bones ;  its  liga- 
ments are  : 

An  interosseous  Jib ro-cartilage,  or  interpuhic  disk. 

A  suprapubic,  extending  along  the  crest  of  the  pubes  on 
each  side,  blendino;  with  the  fibro-cartilao-e. 

K  posterior,  little  more  than  periosteum. 

An  anterior,  thick,  strong,  decussating,  attached  to  the  con- 
tiguous portions  of  the  body  and  rami. 

An  inferior,  or  subpubic,  arched,  filling  up  the  angle  between 
the  pubic  rami ;   nerves  and  arteries  of  no  special  moment. 

The  obturator  iij((nie/it^  is  a  fibrous  membrane  filling  the 
same  named  foramen,  except  at  the  upper  and  outer  part. 

The  Articulations  of  the  Upper  Extremity. 

Describe  the  stemo-clavicular  articulation. 

An  arthrodial  joint  formed  between  the  sternal  end  of  the 
clavicle  and  the  sternum  and  cartilage  of  the  first  rib,  having 
an  interarticular  fibro-cartilage  usually  dividing  the  joint  into 
two  distinct  synovial  sacs  ;  its  ligaments  are  : 

A  capsular,  passing  between  the  articular  margins  and  firmly 
connected  with  the  fibro-cartilage.  Its  strengthening  bands  are 
the  anterior  and  posterior  stemo-clavicular  ligaments. 

The  inter clavicidar,  passing  from  the  posterior  superior  angle 
of  the  inner  extremity  of  each  clavicle,  and  attached  to  the 
sternum  between. 

The  rhomboid,  or  chondro-clavicular,  stretching  from  the 
upper  border  of  the  first  costal  cartilage  to  the  rhomboid 
impression  of  the  clavicle ;  nerves,  from  the  descendens  cervicalis 
and  from  the  nerve  to  the  subclavius ;  arteries,  contiguous 
muscular  branches. 

Describe  the  acromio-clavicular  articulation. 

An  arthrodial  joint  formed  by  the  outer  extremity  of  the 
clavicle  and  the  acromion  process  of  the  scapula  ;  it  rarely  has 
complete  interarticular  fibro-cartilage  and  two  synovial  sacs, 


ARTICULATIONS  OF  THE  UPPER   EXTREMITY.     127 

otherwise  there  is  only  one  sac  ;  its  ligaments  are,  the  capsular^ 
attached  to  the  anterior  and  posterior  borders,  upper  and  lower 
surfaces  of  the  acromion  and  clavicle  ;  the  superior  and  inferior 
acromio-clavicular  ligamentii. 

The  cor((co-clavicul<ir'\  composed  of  the  couoicP,  conical,  at- 
tached by  its  apex  to  the  base  of  the  coracoid  process,  by  its 
base  to  the  conoid  tubercle  of  the  clavicle  and  a  line  internal 
to  it  (Fig.  79). 

The  trapezoid,  broad  and  thin,  quadrilateral,  stretching  be- 
tween a  ridge  on  the  upper  surface  of  the  coracoid  to  an  ob- 
lique line  on  the  under  surface  of  the  clavicle  ;  iwrves,  supra- 
scapular and  circumflex  ;  arteries,  suprascapular,  anterior  cir- 
cumflex, acromio-thoracic. 

What  are  the  proper  ligaments  of  the  scapula? 

The  coraco-acromiai\  a  triangular  flat  band,  attached  by  its 
apex  to  the  summit  of  the  acromion,  by  its  base  all  along  the 
outer  border  of  the  coracoid  process.  Its  anterior  and  poste- 
rior edges  are  thick  and  its  center  thin.  The  superior  transverse 
ligament  bridges  the  suprascapular  notch.  It  has  two  bands. 
The  inferior  transverse,  or  spina-glenoid,  is  near  the  base  of  the 
spine  in  the  infraspinous  fossa.  The  glenoid  belongs  properly 
to  the  scapula,  but  is  described  with  the  shoulder-joint. 

Describe  the  shoulder-joint  (Fig.  79). 

An  enartlirodiid  joint  formed  by  the  head  of  the  humerus 
and  glenoid  fossa  of  the  scapula.  Its  synovial  membrane  is 
reflected  upon  the  tendons  of  the  biceps  and  subscapularis,  and 
the  joint  has  numerous  bursae  in  its  vicinity,  with  some  of 
which  it  communicates,  notably  the  subcoracoid  and  subscapu- 
lar ;  the  ligaments  are,  capsular^,  from  the  margin  of  the  gle- 
noid fossa  above,  to  the  anatomical  neck  of  the  humerus  below. 
Strengthening  bands  are  outside  and  inside  the  capsule ;  the 
former  are  coraco-]nrnier<d^.  transverse  hmneral  ligaments,  and 
surrounding  tendons.  Within  the  joint-cavity  are  three  gleno- 
hnmeral  ligaments  ;  the  ni>i>er  one,  or  Flood's,  is  just  below  and 
parallel  to  the  biceps  tendon  ;  the  middle  one,  or  internal  of 
Sehlenmi,  is  oblirjue  ;  the  inferior  gleno-himeral  is  the  inferior 
or  hroad  ligament  of  Scldemm. 

The  glf'iioid  is  a  dense  fibro-cartilage,  triangular  in  cross-sec- 
tion, attached  to  the  circumference  of  the  fossa,  deepening  the 


128 


ESSENTIALS  OF   HUMAN   ANATOMY. 


socket,  and  continuous  above  with  the  long  head  of  the  biceps 
muscle',  which  really  serves  as  one  of  the  cldef  ii(/amenfs ; 
nerves,  suprascapular,  circumflex,  subscapulars  ;  arteries,  supra- 
scapular, subscapular,  dorsalis  scapulae,  anterior  and  posterior 
circumflex. 

Describe  the  elbow-joint  iFig.  80). 

Ginglymoid,  formed  by  the  lower  end  of  the  humerus, 
greater  and  lesser  sigmoid  cavities  of  the  ulna  and  head  of  the 
radius ;  its  ligaments  are  : 


Fig. 


79  —Left  shoulder-joint  and  scap- 
ular ligaments 


Fig.  80.— Left  elbow-joint, 
antero-internal  aspect. 


A  capsule^,  large,  capacious,  and  usually  described  as  show- 
ing (interior,  posterior,  intenuiK  and  external  ligaments. 

The  anterior  ligament  ^  extends  from  the  humerus,  above  the 
articular  surface  and  coronoid  fossa,  to  the  front  of  the  coronoid 
process  of  the  ulna  and  orbicular  ligament. 

The  posterior  ligament  extends  from  the  back  of  the  humerus, 
from  condyle  to  condyle,  and  through  the  olecranon  fossa,  to 
be  attached  all  around  the  olecranon  process,  close  to  its  articu- 


ARTICULATIONS  OF   THP:    UPPER   EXTREMITY.     129 

lar  margin,  a  few  fibers  to  the  back  of  the  neck  of  the  radius 
and  to  the  orbicular  ligament. 

The  external  hiteral  radiates  from  the  lower  part  of  the  con- 
dyle to  end  in  the  orbicular  ligament,  sending  a  few  fibers  to 
the  neck  of  the  radius  and  interosseous  border  of  the  ulna. 

The  internal  lateral'^  triangular,  rises  from  the  anteroinferior 
aspect  of  the  inner  epicondyle,  and  is  attached  to  the  inner  side 
of  the  coronoid  and  olecranon  processes.  There  are  three 
sets  of  fibers  :  humero-coronoid,  humero-olecranon^  and  ( a  trans- 
verse set)  olecrano-coronoiil ;  nerves,  musculo-cutaneous,  ulnar, 
median,  musculo-spiral ;  arteries,  the  two  profunda  arteries, 
anastomotica  magna,  anterior  and  posterior  ulnar  recurrent, 
posterior  interosseous  recurrent,  radial  recurrent,  and  some 
muscular   branches. 

Describe  the  superior  radio-ulnar  articulation. 

It  is  a  diarthrosis  rotatoria,  or  tvoclioideii,  formed  by  the 
head  of  the  radius  and  lesser  sigmoid  cavity  of  the  ulna,  its 
synovial  membrane  being  continuous  with  that  of  the  elbow- 
joint  ;  its  only  ligament  is  the 

Orhicular^,  surrounding  the  head  of  the  radius,  forming  only 
four-fifths  of  a  circle  by  most  of  its  fibers,  but  some,  continued 
below  the  sigmoid  cavity,  form  a  complete  circle  ;  nerves  and 
arteries  as  above.  This  ligament  and  articulation  belong  to  the 
elbow-joint. 

Describe  the  inferior  radio-ulnar  articulation. 

A  lateral  ginglyraus,  formed  by  the  ulnar  head  and  sigmoid 
cavity  of  the  radius  ;  its  synovial  membrane  is  so  loose  as  to  be 
called  the  niendjrana  sacciformis  ;   the  ligaments  are  : 

The  triangular  Jibro-cartilage  attached  by  its  apex  to  the 
fossa  at  the  base  and  to  the  apex  of  the  styloid  process  of  the 
ulna,  by  its  base  to  the  margin  of  the  radius  below  the  sigmoid 
cavity. 

The  anterior  radio-ulnar  stretches  between  the  anterior  edge 
of  the  sigmoid  cavity  of  the  radius  to  the  rough  surface  above 
the  articular  surface  of  the  ulna. 

The  posterior  radio-idnar  is  similarly  attached  behind  ;  nerves, 
anterior  interosseous  of  the  median  and  posterior  interosseous 
of   the  musculo-spiral  ;    arteries,  anterior  and   posterior  inter- 
osseous and  carpal  arches. 
9 


130  ESSENTIALS  OF  PIUMAN   ANATOMY. 

What  other  ligaments  bind  the  radius  and  ulna  together? 

The  interoaseous  membrane^,  passing  obliquely  downward 
and  inward  from  the  interosseous  ridge  of  the  radius  to 
that  of  the  ulna. 

The  ohllqw'\  attached  to  the  tubercle  at  the  base  of  the 
coronoid  process  of  the  ulna  above,  and  below  to  the  shaft  of 
the  radius  a  little  below  its  tuberosity  ;  nerves  and  arteries  are 
from  the  anterior  interosseous  nerve  and  artery. 

Describe  the  wrist-joint. 

It  is  a  amdijloid  articulation  with  elliptical  surfaces.  Its 
motions  are  flexion  and  extension,  adduction  and  abduction,  a 
combination  of  these  producing  circumduction.  It  has  no  rota- 
tion ;  this  is  accomplished  by  supination  and  pronation  of  the 
bones  of  the  forearm.  It  is  formed  between  the  radius  and 
triangular  fibro-cartilage  above,  and  the  scaphoid,  semilunar, 
and  cuneiform  below  ;  its  ligaments  are,  cajysnlar^  with  four 
strengthening  bands,  an  anterior  radio-carpal^  passing  between 
the  radius,  the  styloid  process  of  the  ulna,  and  the  fibro-carti- 
lage to  the  first  and  second  rows  of  the  carpal  bones. 

A  posterior  radio-carpal  is  similarly  disposed,  passing  from 
the  radius  to  the  first  three  carpals. 

An  internal  lateral,  fan-shaped,  passing  from  the  styloid 
process  of  the  ulna  to  the  pisiform,  and  the  side  and  back  of 
the  cuneiform  bone. 

An  external  lateral,  radiating  from  the  tip  and  front  of  the 
styloid  process  of  the  radius  to  the  scaphoid,  os  magnum,  and 
trapezium  ;  the  posterior  annidar  ligament  also  assists  the  wrist- 
ligaments  proper;  nerves,  ulnar,  median,  and  posterior  inter- 
osseous ;  arteries,  anterior  and  posterior  carpal  arches,  anterior 
and  posterior  interosseous. 

Describe  the  carpal  articulations. 

Arthrodial,  they  consist  of  (1)  the  joints  between  the  bones 
of  the  first  row  ;  (2)  those  between  the  bones  of  the  second  ; 
and  (3)  those  between  the  two  rows,  the  medio-carpal. 

(1)  The  pisiform  has  a  separate  capsular  ligament,  with  two 
bands  connecting  it  with  the  unciform  and  base  of  the  fifth 
metacarpal,  and  a  separate  synovial  membrane  ;  the  other  three 
bones  of  this  row  are  connected  by 


ARTICULATIONS  OF  THE   UPPER   EXTREMITY.    131 

Two  interosseous  ligaments^  between  the  scaphoid  and  lunar, 
and  the   lunar  and  cuneiform  ;  and 

Two  dorsal  and  tioo  palmar  ligaments,  binding  together  the 
same  bones. 

(2)  The  four  bones  of  the  second  row  have 

Two  or  three  interosseous  ligaments^  connecting  the  os  mag- 
num with  the  trapezoid  externally  (inconstant),  the  unciform 
internally  ;  a  third  between  the  trapezium  and  trapezoid  ;  and 

Three  dorsal  and  tltree  palmar  ligaments,  passing  between 
the  contiguous  bony  surfaces. 

(3)  The  two  rows  are  united  by  the  dorsal  and  palmar  liga- 
ments and  two  lateral,  continuous  with  those  of  the  wrist- 
joint  ;  the  anterior  annular  ligament,  passing  from  the  hook  of 
the  unciform  and  from  the  pisiform  to  the  trapezium  and 
scaphoid  bones,  is  an  important  carpal  ligament.  The  synovi<d 
membrane  is  common  to  all  the  carpal  joints,  except  the 
pisiform ;  nerves,  posterior  interosseous,  median  and  ulnar  ; 
arteries,  anterior  and  posterior  carpals  of  the  radial  and  ulnar, 
carpal  of  the  anterior  interosseous,  carpal  of  the  deep  palmar 
arch,  and  terminal  twigs  of  the  anterior  and  posterior  inter- 
osseous. 

Describe  the  carpo-metacarpal  articulations. 

That  of  the  thumb  is  one  of  reciprocal  reception,  and  enjoys 
all  movements  but  rotation  of  the  metacarpal  on  its  own  axis ; 
it  possesses  a  distinct  synovial  sac,  and  its  only  ligament  is  the 

Capsule  attached  around  the  articular  surfaces  of  the  trape- 
zium and  first  metacarpal. 

The  other  four  metacarpals  from  arthrodial  joints  with  the 
adjacent  carpal  bones,  with  three  dorscd  ligaments  passing 
from  the  trapezium,  trapezoid,  and  os  magnum  to  the  second 
bone ;  tvxj  ligaments  from  the  os  magnum  to  third  ;  two  liga- 
ments— one  from  the  magnum,  the  other  from  the  unciform 
— to  fourth  ;  one  ligament  connecting  with  the  fifth  metacarpal 
and   unciform. 

One  palmar  ligament  passes  from  the  trapezium  to  the 
second  metacarpal ;  'one  ligament  each  from  the  trapezium, 
magnum,  and  unciform  to  the  third  ;  one  ligament  connects  the 
unciform  and  fourth  bone ;  one  ligament  passes  from  the 
unciform  to  the  fifth  metacarpal. 

An    interosseous  ligament   connects  the  contiguous    inferior 


132  ESSENTIALS  OF  HUMAN   ANATOMY. 

angles  of  the  os  magnum  and  uiiciforni  with  the  adjacent  sur- 
faces of  the  third  and  fourth  metacarpal  bones  ;  the  mjuovial 
membrane  is  that  common  to  intercarpal  joints,  sometimes  the 
joint  formed  between  the  fourth  and  fifth  metacarpals  and 
unciform  forms  a  separate  synovial  sac  ;  nerves  and  arteries  are 
the  same  as  those  for  the  medio-carpal  joint. 

Describe    the   union    of    the    metacarpal    bones   with    one 
another. 

That  of  the  thumb  is  isolated  ;  the  bases  of  the  others  are  in 
contact,  forming  artlirodtal  joints,  lined  by  prolongations  of 
the  synovial  sac  of  the  carpus,  and  are  bound  together  by  j)al- 
mar^  dorsal^  and  interosseous  ligaments ;  the  deep  transverse 
ligament  binds  together  their  heads ;  it  is  a  part  of  the 
palmar  fascia. 

Describe    the    metacarpo-phalangeal    and     interphalangeal 
articulations. 

They  are  glnghjmo-arthrodlal^  connected  by  tiro  lateral  liga- 
ments and  an  anterior  Jihro-cartllage,  or  glenoid  ligament^ 
except  for  the  thumb,  where  this  is  replaced  by  two  sesamoid 
bones,  while  behind  an  expansion  of  the  extensor  tendon  and 
some  loose  areolar  tissue  completes  each  little  synovial  capsule  ; 
nerves  and  arteries  are  from  the  digitals  ;  the  Interphalangeal 
joints  resemble  the  metacarpo-phalangeal  in  regard  to  liga- 
ments ;  they  are  true  hinge-joints  (^glngli/mus). 

The  Articulations  of  the  Lower  Extremity. 

Describe  the  hip-joint. 

An  enarthrodlal,  but  not  so  freely  moving  joint  as  that  of 
the  shoulder ;  it  is  formed  by  the  head  of  the  femur  and  the 
acetabulum  of  the  os  innominatum  ;  the  ligaments  are  (Fig.  81): 

The  cajw?</ar^,  arising  near  to  the  acetabular  margin,  and 
from  the  outer  surface  of  the  transverse  ligament ;  it  is  attached 
to  the  femur  in  front  to  the  trochanter  major  and  spiral  line, 
and  behind  to  the  neck  about  half  an  inch  from  the  posterior 
intertrochanteric  line  ;  it  is  thence  reflected  like  a  tube  up  to 
the  head  of  the  femur.  The  capsule  has  accessory  ligaments 
from  the  three  bones  of  the  os  innominatum,  lllo-femoral,  illo- 
trochanterlc.  pubo-femoral,  ischio-capsular. 

The  illo-femoraP^  or  Y-llgament,  arising  from  the  anterior  infe- 


ARTICULATIONS  OF  THE   LOWER   EXTREMITY.     133 

rior  iliac  spine  to  be  attached  to  the  spiral  line,  the  outer  and 
inner  margins  so  well  marked  as  to  seem  like  distinct  liga- 
mentous bands  showing  the  capsule  between. 

The  Hgamentum  terea^^,  arising  by  separate  heads  from  each 
side  of  the  cotyloid  notch  externally,  passes  beneath  the  trans- 
verse ligament  rising  from  it  and  the  fossa  acetabuli  covered 
by  the  synovial  membrane,  and  is  attached  to  the  fossa  capitis 
of  the  femur. 

Cotyloid,  a  marginal  fibro-cartilage  attached  all  around  the 
acetabular  margin,  forms  the  transverse  ligament  below,  deepen- 
ino-  the  socket. 

Transverse,  is  a  ligamentous  band  of  the  cotyloid  bridging 
the  cotyloid  notch,  converting  it  into  a  foramen  ;  nerves,  from 
the  anterior  crural  by  branch  to  rectus,  obturator,  accessory 
obturator,   nerve  to   the   quadratus  femoris,  great    sciatic   or 


Fig.  81.— Hip-joints,  anterior  view. 

lower  part  of  the  sacral  plexus ;  arteries,  internal  and  external 
circumflex,  obturator,  gluteal,  and  sciatic.  The  synovial  mem- 
brane commonly  communicates  with  the  bursa  beneath  the 
ilio-psoas  muscle. 

Describe  the  knee-joint. 

(iinffJymoid,  formed  by  condyles  of  the  femur,  upper  surface 
of  the  tibial  head,  and  patella,  it  has  the  largest  synovial  sac  o^ 


134  ESSENTIALS  OF  HUMAN  ANATOMY. 

any  joint,  sending  a  prolongation  beneath  the  popliteus  muscle 
and  another  two  or  three  inches  up  the  front  of  the  femur, 
beneath  the  quadriceps  tendon,  the  snhcrural  bursa  or  pouch; 
the  bursa  between  the  semimembranosus  and  internal  head  of 
the  gastrocnemius  and  inner  condyle  usually  communicates 
with  the  joint,  and  often  one  or  more  of  the  remaining  bursae 
near  the  articulation  ;  its  ligaments  consist  of 

An  anterior  or  ligamentum  patdla:,^  (Fig.  83),  a  continuation 
of  the  quadriceps  tendon  attached  to  the  tubercle  of  the  tibia 
below,  which,  wn'th  the  fibrous  hood  formed  by  the  two  vasti 
tendons  attached  to  the  patellar  margins  and  the  oblique  lines 
on  the  head  of  the  tibia  extending  upward  from  the  tubercle, 
cover  in  the  joint  in  front  blending  with  the  lateral  ligaments. 

The  posterior  or  ligamentum  ]yinslowii^j  formed  of  dense, 
interlacing  fibers,  having  incorporated  with  it  part  of  the  semi- 
membranosus tendon  ^  (Fig.  82),  extends  from  the  femur  to  the 
tibia  and  from  the  external  to  the  internal  lateral  ligaments. 
The  popliteal  oblique  ligament  passes  from  the  back  part  of  the 
inner  tuberosity  of  the  tibia,  connected  with  the  semimem- 
branosus upward  and  outward,  within  the  intercondyloid  notch, 
to  the  back  part  of  the  external  condyle  of  the  femur.  The 
ligamentum  arcuatum  is  sometimes  present  below  the  oblique 
ligament  convex  inferiorly. 

The  internal  lateral^,  a  strong  flat  band  passing  from  the 
depression  on  the  inner  femoral  epicondyle  to  the  inner  border 
and  surface  of  the  shaft  of  the  tibia  for  two  or  three  inches 
(5—8  cm.)  below  the  articular  surface;  it  is  attached  to  the 
internal  semilunar  fibro-cartilage. 

The  external  lateral  ligaments  are  two  in  number : 

The  long^^  a  rounded  cord  attached  above  to  external  epi- 
condyle of  the  femur,  below  to  the  outer  part  of  the  head  of 
the  fibula,  splitting  the  tendon  of  the  biceps ; 

The  sliort^  behind  and  parallel  to  the  above,  attached  above 
to  the  lower  part  of  the  outer  femoral  condyle,  below  to  the 
summit  of  the  styloid  process  of  the  fibula  ;  it  joins  the 
arcuate  above  when  that  is  present.  All  the  preceding  liga- 
ments are  accessory  to  and  strengthen  the 

Capsular  ligament,  within  which  are  the  internal  liaauients 
(Fig.  83). 

The  anterior  crucial-,  from  the  inner  side  of  the  depression 
in  front  of  the  spine  of  the  tibia,  passes  upward,  backward,  and 


ARTICULATIONS  OF  THE  LOWER   EXTREMITY.     135 

outward  to  the  inner  siirikce  of  the  back  part  of  the  outer  con- 
dyle of  the  femur. 

The  posterior  crucial  \  from  back  part  of  the  depression 
behind  the  tibial  spine  and  popliteal  notch  to  the  outer  fore 
part  of  the  inner  condyle— both  crucial  ligaments  are  attached 
to  the  respective  extremities  of  the  external  semilunar  fibro- 


FiG  82.— Riffht  knee-joint,  posterior       Fig.  8.3.— Right  knee-joint  show- 
view.  (Leidy.)      ing  internal  ligaments. 

cartilage.  The  tibers  from  the  external  cartilage  to  the  poste- 
rior crucial  are  called  the  third  crucial  or  ligament  of  Wrisberg. 

Tiro  semilunar  Jiljro-carfilageH\\  attached  by  the  extremities 
to  the  depressions  in  front  and  behind  the  spine  of  the  tibia  ; 
they  serve  to  deepen  the  sockets  for  the  femoral  condyles,  and 
are  attached  to  the  head  of  the  tibia  by  the  coronary  ligaments, 
short  bands  passing  between  their  outer  margins  and  the  tibial 
head  ;  they  are  also  connected  to  one  another,  in  front,  by  the 
small  band-like  fransrrrsc  ligament  *. 

Stretching  from  the  front  of  the  joint,  below  the  patella,  to 
the  front  of  the  intercondyloid  notch,  is  the  triangular  fold  of 
the  synovial  membrane  calltMl  the  ligamentum.  miicosum,  from 
whose  sides  extend  ujtward  and  outward  to  the  sides  of  the 
patella  the  fringe-like  folds  termed  ligameuta  alaria. 

Nerves,  internal   and   external   poplitOMl.  anterior  crural,  ob- 


136  ESSENTIALS  OF  HUMAN  ANATOMY. 

turator ;  arteries^  five  articular  from  popliteal,  aiiastomotica 
magna  from  femoral,  two  recurrents  from  anterior  tibial,  ex- 
ternal circumflex,  and  fourth  perforating  of  profunda.  The 
InivHsc  in  relation  to  the  joint  are  numerous  :  three  prepatellar, 
three  pretibial,  one  subcrural,  four  placed  externally  and  five 
internally. 

Describe  the  superior  tibio-fibular  articulation. 

Arthrodial,  formed  between  the  facets  on  the  fibular  head 
and  outer  tuberosity  of  the  tibia,  its  ligaments  are  really  a 
ccq^side.  described  as 

Anterior  superior  tthw-jihular  ^°  (F^g-  S*^)?  directed  obliquely 
upward  and  inward  from  the  fibula  to  the  tibia. 

Posterior  superior  tibio-jihular  ^^  (Fig.  82),  similarly  disposed 
behind  ;  the  synovial  membrane  communicates  with  that  of  the 
knee  in  one  out  of  eighty  specimens  ;  nerves,  from  the  external 
popliteal ;  arteries,  inferior  external  articular,  anterior  and 
posterior  tibial  recurrent. 

Describe  the  so-called  middle  tibio-fibular  articulation. 

The  contiguous  borders  of  the  bones  are  connected  by  the 
interosseous  memhrane^^  (Fig.  88),  deficient  above  for  the 
passage  of  the  anterior  tibial  vessels,  below  it  is  perforated  by 
the  anterior  peroneal  vessels;  its  fibers  pass  from  the  tibia 
downward  and  outward  to  the  fibula. 

Describe  the  inferior  tibio-fibular  joint. 

Syndesmosis,  like  a  suture,  formed  superiorly  by  the  rough 
surfaces  of  the  contiguous  bones,  below  by  small  cartilage- 
coated  surfaces ;  its  limited  synovial  membrane  is  part  of  that 
of  the  ankle. 

The  ligaments  are : 

Inferior  interosseons,  which  is  really  part  of  the  interosseous 
membrane,  passing  between  the  rough  surfaces  of  the  two 
bones. 

Anterior  and  posterior  inferior  tihio-Jihidar,  oblique  fibrous 
bands  binding  together  the  contiguous  bony  surfaces  in  front 
and  behind. 

Transverse,  a  narrow  band  passing  from  the  external  malle- 
olus to  the  tibia  behind  the  joint;  nerves,  those  of  the  ankle; 
arteries,  anterior  and  posterior  peroneal  and  external  malleolar. 


ARTICULATIONS  OF  THE   LOWER   EXTREMITY.     137 

Describe  the  ankle-joint. 

Guiglymoid,  formed  by  the  lower  end  of  the  tibia  with  its 
malleolus  and  the  external  malleolus,  and  the  upper  surface 
and  sides  of  the  astragalus  ;   its  ligaments  are  the 

Anterior'*  (Fig-  8-1),  connecting  the  articular  margins  of  the 
tibia  and  fibula  with  the  rough  upper  surface  of  the  astragalus. 

Posterior'^  (Fig-  84),  thin  and  imperfect,  extends  between 


Fig.  84.— Right  ankle-joint,  in- 
ternal view. 


(Leidy.) 


Fig.  85.— Right  ankle-joint,  ex- 
ternal view. 


the  external  malleolus,  lower  end  of  the  tibia  and  posterior  tibio- 
fibular ligament  above ;  below,  to  the  posterior  surface  of  the 
astragalus  from  one  lateral  ligament  to  the  other. 

Interned  lateral^  (Fig-  84),  (deltoid)  radiates  from  the  lower 
border  of  the  inner  malleolus  to  the  astragalus  behind,  in  front 
to  the  navicular,  and  between  to  the  os  calcis.  It  has  a  deep 
set  of  fibers  from  the  malleolus  to  the  astragalus. 

External  lateral'^^^  (Fig.  85),  composed  of  three  fa.sciculi 
from  the  anterior  margin,  apex,  and  back  of  the  external  mal- 
leolus; it  is  attached  to  the  astragalus  and  the  os  calcis  ;  nerves, 
internal  saphenous,  anterior  and  posterior  tibial ;  arteries,  ante- 
rior and  posterior  tibial,  anterior  and  posterior  peroneal. 

Describe  the  tarsal  joints. 

Those  of  the  first  rcnv  are  arthrodial ;  the  astragalus  and 
calcis  have  three  ligaments: 

ErJernal  rdlcaneo-astrnrfdloid,  from  the  outer  surface  of  the 
astragalus  to  the  outer  surface  of  the  calcis. 

The  posterior  calcaneo-astraffaloid  connects  the  posterior  tu- 
bercle of  the  astragalus  with  the  upper  surface  of  the  calcis. 


138  ESSENTIALS  OF  HUMAN   ANATOMY. 

The  internal  caJcaneo-astragahtid  connects  the  back  of  the 
astragalus  to  the  sustentaculum  tali. 

The  interosseous,  the  chief  bond,  filling  up  the  groove  on  the 
under  surface  of  the  astragalus  and  upper  one  of  the  calcis ; 
there  are  two  synovial  sacs,  one  posterior,  the  other  anterior, 
continued  between  the  astragalus  and  navicular ;  nerves,  poste- 
rior tibial  or  plantar;  arteries,  posterior  tibial,  tarsal,  external 
malleolar  (from  anterior  tibial),  and  terminal  twigs  of  the 
peroneal. 

Joints  of  the  second  row,  navicular,  cuboid,  and  cuneiforms, 
have 

Dorsal  ligaments,  small  bands  connecting  the  contiguous 
bones,  and 

Plantar  ligaments,  similarly  disposed ;  also  four 

Interosseous  ligaments,  connecting  the  sides  of  the  navicular 
and  cuboid,  the  internal  and  middle  cuneiform,  the  middle  and 
external  cuneiform,  the  external  cuneiform  and  cuboid;  nerves, 
anterior  tibial,  internal  and  external  plantar ;  arteries,  meta- 
tarsal and  plantars. 

Joints  between  the  two  rows,  or  medio-tarsal :  (1)  The  cal- 
caneo-cuhoid,  artltrodial,  has 

The  superior  calcaneo-cuhoid  ligament,  connecting  the  dorsal 
surfaces  of  the  calcis  and  cuboid. 

The  internal  (^interosseous)  calcaneo-euhoid,  connecting  the 
inner  part  of  the  front  of  the  calcis  with  the  postero-internal 
angle  and  contiguous  part  of  the  cuboid. 

The  long  calcaneo-cuhoid  (plantar)  arises  from  the  under 
surface  of  the  calcis  between  the  posterior  tubercles  and  the 
anterior  tubercle,  to  be  attached  to  the  oblique  ridge  of  the 
cuboid  and  bases  of  the  second,  third,  fourth,  and  fifth  meta- 
tarsal bones,  completing  a  canal  for  the  long  peroneal  tendon. 

The  short  plantar  arises  from  the  anterior  calcaneal  tubercle 
and  the  bone  in  front,  to  be  attached  to  the  under  surface 
of  the  cuboid  behind  the  ridge,  except  at  the  outer  angle  ; 
the  synovial  sac  is  distinct  from  that  of  the  other  tarsal 
joints. 

(2)  The  astragalo-navicula r  articulation  is  the  only  enarthro- 
dial  (ball-and-socket)  joint  of  the  tarsus;  its  only  ligament  is 
th'3  superior  astragalo-navicular. 

The  ligaments  connecting  the  os  calcis  and  navicular  are 

The  superior  calca nco-navicular ,  dense  and  thick,  extending 


ARTICULATIONS  OF  THE  LOWER   EXTREMITY.     139 

from  the  anterior  iiiternal  extremity  of  the  calcis  to  the  outer 
surface  of  the  navicular. 

The  inferior  cdlcanco-iuiviciflar,  passing  ol)liquely  forward 
from  the  sustentaculum  tali  to  the  under  surface  of  the  navic- 
ular ;  nerves  of  the  medio-tarsal  joint  are  the  external  branch 
of  the  anterior  tibial,  sometimes  the  musculo-cutaneous  or 
external  plantar;  arteries,  anterior  tibial,  tarsal,  metatarsal, 
external,  and  internal   plantar. 

Describe  the  tarso -metatarsal  articulations. 

ArtJiro(/i(/l,  between  the  three  cuneiforms  and  the  cuboid, 
and  the  bases  of  the  five  metatarsals  ;  their  ligaments  are  : 

Dorsal,  one  between  the  first  metatarsal  and  internal  cunei- 
form ;  one  from  each  cuneiform  to  the  second  ;  one  each  from 
the  external  cuneiform  to  the  third  and  fourth  ;  one  each  from 
the  cuboid  to  the  fourth  and  fifth  metatarsals. 

Plantar,  more  irregularly  disposed  ligamentous  fibers. 

Interosseous,  one  connecting  the  outer  extremity  of  the  inner 
cuneiform  to  the  adjacent  angle  of  the  second  metatarsal ;  one 
between  the  outer  cuneiform  and  the  adjacent  angle  of  the  sec- 
ond metatarsal;  one  connecting  the  outer  angle  of  the  external 
cuneiform  with  side  of  the  third  metatarsal  ;  nerves,  anterior 
tibial  and  plantars ;  a7-teries,  from  the  dorsalis  y)edis  })y  the 
metatarsal,   deep  plantar  arch,  and  internal   plantar. 

Describe  the  articulations  of  the  metatarsal  bones  with  each 
other. 
Except  the  first,  their  bases  are  bound  together  by  tlx;  dor- 
sal, plantar,  anil  interosseous  ligaments;  tlie  distal  extremities 
are  united  by  the  deep  transverse  metatarsal  ligament. 

Describe  the  metatarso-phalangeal  and  the  interphalangeal 
articulations. 

They  resem})le  in  all  respects  tliose  of  the  liand  (which  see). 

How  many  distinct  synovial  sacs  have  the  tarsus  and  the 
metatarsus  ? 
Six,  viz.:  (1)  between  the  calcis  and  the  astragalus,  poste- 
rior to  the  inteross(!OUH  ligament;  (2)  in  front  of  the  same 
ligament,  between  the  calcis  and  the  astragalus,  also  betwcsen 
the  astragalus  and  navicular;  (8)  between  the  calcis  and  the 
cuboid  ;  (\)  })etween  th(!  navicular,  cuboid,  nnd  the  cuneiforms. 


140  ESSENTIALS  OF  HUMAN  ANATOMY. 

communicating  between  tlie  middle  and  the  external  cunei- 
forms with  the  joints  formed  between  those  bones  and  the  bases 
of  the  second  and  third  metatarsals ;  (5)  between  the  sides 
and  bases  of  the  fourth  and  fifth  metatarsals  and  the  cuboid  ; 
(())  between  the  base  of  the  first  metatarsal  and  the  internal 
cuneiform. 

MUSCLES   AND   FASCI/E. 

What  is  a  muscle  ? 

It  is  a  structure  connected  with  bones,  cartilages,  ligaments, 
or  skin,  directly  or  through  the  medium  of  a  tendon  or  apo- 
neurosis ;  the  structure  is  capable  of  shortening  when  irritated 
mechanically  or  by  nerve-stimulus,  this  property  being  called 
muscular  coatractUity  or  irritahiHty. 

How  are  muscles  divided? 

According  to  their  form,  into  narrow,  broad,  penniform  (when 
their  fibers  converge  like  the  plumes  of  a  pen  to  one  side  of  the 
tendon)  ;  hipenniform  when  so  arranged  on  both  sides  of  a  ten- 
don, radiated;  also  named  from  situation,  direction,  use,  size, 
or  attachments. 

What  are  the  varieties  of  muscular  tissue  ? 

There  are  two^  one  variety  consisting  of  prismatic  fasciculi 
about  4^oth  of  an  inch  in  diameter,  marked  by  transverse 
striae,  each  bundle  surrounded  by  a  sheath  ov  perimysium  ;  each 
fasciculus  is  formed  of  a  number  of  Jihrillse,,  Ts^io^o^^^  ^^  ^"  '\i\Qh. 
in  diameter,  surrounded  by  a  tubular,  transparent  elastic  mem- 
branous sarcolemma.  Every  fibril  presents  alternating  dark 
and  light  zones  ;  the  former  is  the  frausverse  disk  ;  in  its  center 
is  a  transverse  lighter  band,  Flensen's  line.  The  light  zone  is 
divided  into  two  lateral  disks  by  a  dark  line  called  the  inter- 
mediate disk,  or  Kranse's  memhrane.  A  sarcous  element  of  Bow- 
man is  the  part  included  between  two  lines  of  Krause.  This 
variety  of  tissue  forms  the  vohiutary,  striped  mnscles,  or  those 
of  animal  life,  being  under  the  control  of  the  will ;  the  invol- 
untary, nnstripcd,  or  the  muscles  of  organic  life,  are  not  under 
the  control  of  the  will,  and  consist  of  elongated,  spindle-shaped, 
flattened,  nucleated  cells,  R-Jo^th  to  gj^th  of  an  inch  long, 
-j^T^j-Qth  to  Tj ^Q^th  broad,  and  are  held  together  in  bundles  by  a 
cement-substance  containing  a  few  connective-tissue  corpuscles, 


MUSCLES   AND   FASCIA.  141 

the  bundles  being  further  collected  into  larger  fasciculi,  or 
flattened  bands,  bound  together  by  ordinary  areolar  tissue  ;  this 
kind  of  muscle  is  that  found  forming  the  contractile  coats  of 
the  stomach,  intestines,  bladder,  arteries,  veins,  lymphatics, 
ureters,  urethra,  iris,  ciliary  body,  etc.  ;  when  irritated  a  part 
contracts  and  slowly  relaxes,  while  another  contiguous  portion 
is  contracting,  which  action  being  continued  produces  the 
vermicular  (worm-like),  peristaltic  movements  of  the  intestines. 
The  spontaneously  coagulable  albuminous  substance  composing 
muscle  is  called  myoi^in  ;  so-called  ayntonin  is  a  modification 
produced  by  chemical  agents. 

What  are  tendons  and  aponeuroses  ? 

Tendons  are  glistening  cords  or  bands,  of  white  inelastic 
fibrous  tissue,  almost  without  blood-  or  nerve-supply,  and  con- 
nect the  muscular  tissue  with  the  part  to  be  moved  ;  aponeu- 
roses are  membranous  expansions  of  the  same  tissue  serving 
similar  purposes. 

What  are  the  fasciae? 

They  are  laminae  of  fibrous  or  fibro-areolar  tissue  investing 
the  soft  tissues  ;  the  superficial  fascic^-  are  usually  fibro-areolar, 
lie  beneath  the  skin,  and  are  loaded  with  fat ;  the  deep  fasciaB 
resemble  aponeuroses,  are  dense  and  inelastic,  ensheathing  mus- 
cles, or  serving  for  their  attachment,  and  tend  to  preserve  the 
form  of  the  part,  since  partitions  descend  between  various  mus- 
cles to  become  attached  to  the  periosteum  of  the  osseous  frame- 
work. 

To  what  are  the  tendons  attached? 

To  the  periosteum  and  perichondrium  with  which  they 
become  blended,  to  the  subcutaneous  tissue,  and  to  ligaments. 

What  are  meant  by  the  origin  and  the  insertion  of  a  muscle  ? 
The  orupn  is  the  most  fixed  and  central  point  from  which  the 
muscle  acts  ;  the  insertion  is  the  movable  point  to  which  the 
muscular  force  is  directed  ;  but  in  many  muscular  acts  the 
part  usually  described  as  the  insertion  becomes  the  fixed  point, 
and  the  oriuin  the  movable  one.  Some  muscles  have  double 
origins  and  single  insertions,  as  the  occipito-frontalis,  digastric, 
or  omo-hyoid. 


142  ESSENTIALS  OF  HUMAN   ANATOMY. 

Muscles  of  the  Head. 

Describe  the  origin,  insertion,  action,  and  nerve-supply  of 
the  following  muscles  (Fig.  86j. 

The  facial  nerve  supplies  motion  to  all  the  muscles  of  ex- 
pression ;  the  inferior  maxillary  division  of  the  fifth,  to  all 
muscles  of  mastication  except  the  buccinator. 

Occipito-frontalis  ^ :  origin^  occijntal  portion,  outer  two-thirds 
of  the  superior  curved  line  of  the  occipital  bone  and  mastoid 
process,  insertion  into  the  epicranial  aponeurosis ;  frontal  por- 
tion rises  from  the  epicranial  aponeurosis  and  blends  below  with 
the  eyebrow,  continuous  with  the  pyramidalis  nasi,  interlacing 
with  the  corrugator  supercilii  and  orbicularis  palpebrarum  ; 
action,  raises  the  eyebrows  and  transversely  wrinkles  forehead; 
nerves,  facial,  by  its  posterior  auricular  and  temporal  branches. 

Attolens  aurem*:  origin,  epicranial  aponeurosis;  insertion, 
superior  portion  of  the  pinna  of  the  ear ;  action,  raises  the 
pinna  ;  nerve,  temporal  branch  of  the  facial. 

Atrahens  aurem:  origin,  lateral  margin  of  the  epicranial 
aponeurosis ;  insertion,  a  projection  on  front  of  the  helix  ; 
action,  draws  the  pinna  forward  and  upward  ;  nerve,  facial. 

Retrahens  aurem  ^:  origin,  mastoid  portion  of  the  temporal 
bone  ;  insertion,  lower  part  of  the  concha  ;  action,  draws  ear 
backward ;  nerve,  posterior  auricular  branch  of  the  facial. 

Orbicularis  palpebrarum  "^ :  origin,  internal  angular  process  of 
the  frontal,  nasal  process  of  the  superior  maxillary  bone,  and  the 
anterior  surface  and  margins  of  the  tarsal  ligaments  ;  insertion, 
skin  of  the  eyelids  and  contiguous  portions  of  the  forehead, 
temple,  and  cheek,  blending  with  the  occipito-frontalis  and 
corrugator  supercilii  muscles;  action,  closes  eyelids;  nerve, 
facial. 

Corrugator  supercilii:  origin,  inner  end  of  the  superciliary 
ridge ;  insertion,  upward  and  outward  to  the  under  surface  of  the 
orbicularis  palpebrarum  ;  action,  draws  the  eyebrow  downward 
and  inward  ;  nerve,  facial. 

Tensor  tarsi  (Horner's  muscle)  :  origin,  crest  of  the  lacrimal 
bone  ;  insertion,  by  two  slips  into  the  tarsal  cartilages  near  the 
puncta ;  action,  compresses  the  lacrimal  sac  and  keeps  the 
puncta  in  contact  with  the  globe  ;  nerve,  facial.  (For  occu- 
lar  muscles,  see  p.  355.) 

Levator  palpebrae  superioris^:   origin,  lesser  wing  of  the  sphe- 


MUSCLES   OF   THE   HEAD. 


143 


noid  ;  insertion,  upper  border  of  the  superior  tarsal  cartilage 
and  into  the  skin  ;  action,  elevates  the  upper  lid  ;  nerve,  third 
cranial   (motor  oculi). 


Fig.  86.— Muscles  of  the  head,  face,  and  neck  (Leidy). 

Pyramidalis  nasi  "^ :  origin,  occipito-frontalis  ;  insertion,  into 
the  compressor  naris ;  action,  depresses  the  inner  angle  of  the 
eyebrow  ;   nerve,  facial. 

Levator  labii  superioris  alseque  nasi  ^ :  origin,  upper  part  of  the 
nasal  process  of  the  superior  maxillary  bone  ;  insertion,  the 
cartilage  of  the  ala  of  the  nose,  and  into  the  upper  lip  blending 
with  the  orbicularis  and  levator  labii ;  action,  draws  upward 
the  upper  lip  and  dilates  the  nostril ;  nerve,  facial. 

Dilator  naris  anterior:  origin,  cartilage  of  the  ala;  insertion, 
integument  near  its  margin  ;  action,  dilates  the  nostril  ;  nerve, 
facial. 

Dilator  naris  posterior:  origin,  margin  of  the  nasal  notch  of 
the   superior  maxilhi   and   the   sesamoid   cartilages;    insertion, 


144  ESSENTIALS  OF  HUMAN   ANATOMY. 

skin   near  the  margin  of   the  nostril;  action^  dilates  the  nos- 
tril ;   nerve,  facial. 

Compressor  nasi'':  oritjiii^  above  and  external  to  the  incisive 
fossa  of  the  superior  maxilla  ;  fnf;erfion,  fibro-cartilage  of  the 
nose,  and  is  continuous  with  its  fellow  and  the  aponeurosis  of 
the  pyramidalis  nasi;  r^c^^V>;^  depresses  cartilage,  compresses 
alee,  dilates  nostril,  and  wrinkles  skin;  nerve,  facial. 

Compressor  narium  minor  :  origin,  alar  cartilage ;  insertion, 
skin  of  tip  of  the  nose;  action,  dilates  the  nostril;  nerve, 
facial. 

Depressor  alse  nasi :  origin,  incisive  fossa  of  the  superior 
maxilla  ;  insertion,  septum  and  back  part  of  the  ala  ;  action, 
narrows  the  nostril ;   nerve,  facial. 

Levator  labii  superioris  ^ :  origin,  lower  margin  of  the  orbit 
above  the  infraorbital  foramen  ;  insertion,  muscular  substance 
of  the  upper  lip  ;  action,  elevates  the  lip  ;   nerve,  facial. 

Levator  anguli  oris  ^^ :  origin,  canine  fossa  of  the  superior 
maxilla  ;  insertion,  angle  of  the  mouth  ;  action,  elevates  angle  of 
the  mouth  ;  nerve,  facial. 

Zygomaticus  major  ^^ :  origin,  malar  bone;  insertion,  angle  of 
the  mouth  :  action,  elevates  angle  of  the  lip  ;  nerve,  facial. 

Zygomaticus  minor '^  (inconstant):  origin,  malar  bone  ante- 
riorh^ ;  insertion,  angle  of  the  mouth;  action,  same  as  major; 
nerve,  facial. 

Levator  labii  inferioris  (levator  menti)  :  origin,  incisive  fossa 
of  the  lower  jaw  ;  insertion,  skin  of  the  chin  ;  action,  elevates 
the  chin  and  the  lower  lip  ;   nerve,  facial. 

Depressor  labii  inferioris  ^^'^  (quadratus  menti):  origin,  ex- 
ternal oblique  line  of  the  lower  jaw  ;  insertion,  skin  of  the 
lower  lip;  action,  depresses  the  lower  lip;  ?ie?'?;e.  facial. 

Depressor  anguli  oris  ^* :  origin,  external  oblique  line  of  the 
lower  jaw  ;  insertion,  angle  of  the  mouth  ;  action,  depresses 
angle  of  the  mouth  ;  nerve,  facial. 

Orbicularis  oris  ^^ :  origin,  nasal  septum  and  superior  and  in- 
ferior maxillary  borders  by  accessory  fibers  called  accessorii 
orbicularis  superioi'is  and  inferioris,  and  naso-lahialis  ;  insertion, 
the  buccinator  and  other  muscles  converging  to  the  mouth  ; 
action,  closes  the  mouth  ;  nerve,  facial. 

Buccinator '=«:  origin,  behind,  from  the  pterygo-maxillary  liga- 
ment, above  and  below  the  external  surfaces  of  the  alveolar 
processes  of  the  three  molar  teeth ;  insertion^  orbicularis  oris ; 


MUSCLES  OF  THE  NECK.  145 

action^  compresses  the  cheek  ;  nerve,  facial  and  buccal  branch 
of  the  inferior  maxillary,  the  latter  being  sensory. 

Risorius  (Santorini) :  origin,  fascia  over  the  masseter  muscle- 
insertion,  skin  at  angle  of  the  mouth  ;  action,  laughing  muscle  ; 
nerve,  facial. 

Masseter  1-:  origin,  the  superficial  portion  from  the  malar 
process  of  the  superior  maxilla  and  the  anterior  two-thirds  of 
the  lower  border  of  the  zygomatic  arch,  the  deep  portion  from 
the  posterior  third  of  the  lower  border  and  the  inner  surface 
of  the  zygomatic  arch;  insertion,  into  the  outer  surface  of  the 
ramus,  angle,  and  coronoid  process  of  the  lower  jaw  ;  action, 
raises,  protracts,  and  retracts  the  lower  jaw,  a  masticatory 
muscle  ;   nerve,  inferior  maxillary. 

Temporal:  origin,  temporal  fossa  and  fascia;  insertion,  into 
anterior  border,  apex,  and  inner  surface  of  the  coronoid  process 
of  the  lower  jaw  ;  action,  raises  and  retracts  the  lower  jaw,  a 
muscle  of  mastication  ;  nerve,  inferior  maxillary. 

Internal  pterygoid:  origin,  by  two  heads  from  the  inner  surface 
of  the  external  pterygoid  plate  and  grooved  surface  of  the  pal- 
ate bone,  and  by  a  second  slip  from  the  tuberosity  of  the  palate 
and  superior  maxillary  bones;  insertion,  lower  back  part  of  the 
inner  side  of  the  ramus  and  angle  of  the  jaw  as  high  as  the 
dental  foramen  ;  action,  raises  and  draws  the  lower  jaw  for- 
ward, a  muscle  of  mastication  ;  nerve,  inferior  maxillary. 

External  pterygoid:  origin,  by  two  heads,  one  from  the  infra- 
temporal ridge  on  the  greater  wung  of  the  sphenoid,  and  from  the 
bone  included  between  it  and  the  base  of  the  pterygoid  process, 
the  other  from  the  outer  surface  of  the  external  pterygoid  plate  ; 
insertion,  depression  in  front  of  the  neck  of  the  condyle  of  the 
lower  jaw  and  interarticular  fibro-cartilage  ;  action,  depresses 
and  draws  the  jaw  forward,  a  triturating  masticatory  muscle  ; 
nerve,  inferior  maxillary.  Usually  the  internal  maxillary  artery 
passes  between  the  two  heads  of  this  muscle  :  sometimes  pierces 
it ;  often  lies  below  it. 

Muscles  of  the  Neck. 

Platysma  myoides :  origin,  deep  fascia  over  the  pectoral,  deltoid, 
sterno-niastoid,  and  trapezius  muscles;  insertion,  lower  jaw  be- 
neath the  oblirjue  line,  angle  of  the  mouth,  cellular  tissue,  and 
some  muscles  of  the  face;  ac^<o?<,  wrinkles  skin  of  the  neck  and 
10 


146 


ESSENTIALS  OF  HUMAN   ANATOMY. 


depresses  the  jaw  and  angle  of  the  mouth  ;   iicj-ccs,  facial,  by 
the  inframaxillary  branches. 

Sterno-cleido-mastoid "  (Fig.  87):   origin,  upper  front  part  of 


Fig.  87. — Muscles  of  the  neck,  anterior  view  (Leidy). 


the  sternum,  inner  third  of  upper  border  of  the  clavicle;  inser- 
tion, mastoid  process  of  the  temporal  and  outer  two-thirds  of  the 
superior  curved  line  of  the  occipital  bone  ;  action,  acting  sinffb/, 
flexes  head  sideways,  and  rotates  chin  to  the  opposite  side,  both 
actins:  flex  the  head  on  the  neck,  and  the  neck  on  the  chest ; 
nerves,  spinal  accessory,  second  and  third  cervical  nerves,  ante- 
rior branches. 

Sterno-hyoidi^:  origin,  ribbon-like,  from  the  posterior  surface 
of  the  sternum  and  inner  end  of  the  clavicle  ;  insertion,  body 
of  the  hyoid  bone ;.  action,  depresses  the  hyoid  bone  ;  nerves, 
filaments  from  the  loop  between  the  descendens  and  the  com- 
municans  cervicalis. 

Sterno-thyroid'':  origin,  posterior  surface  of  the  sternum  and 
cartilage  of  the  first  rib,  sotiietimes  from  the  clavicle  ;  i^iser- 
tion,  oblique  line  on  the  ala  of  the  thyroid  cartilage  ;  action, 
depresses  the  larynx  ;  nerves,  same  as  the  sterno-h3^oid. 

Thyro-hyoid'*':  origin,  oblique  line  of  the  thyroid  cartilage; 
insertion,  lower  border  of  the  body  and  greater  cornu  of  the 


MUSCLES  OF  THE   NP]CK.  147 

hyoid  bone  ;  action^  may  elevate  the  larynx  or  depress  the 
hyoid  ;    iwrvc^  descendens  cervicalis. 

Omo-hyoid'^:  orighi^  from  the  upper  border  of  the  scapula 
near  the  suprascapular  notch,  perhaps,  also,  from  the  trans- 
verse ligament ;  insertion^  body  of  the  hyoid  bone,  its  central 
tcnduioiis  imrtloii  being  held  down  by  a  process  of  the  deep 
cervical  fascia  prolonged  down  to  be  attached  to  the  cartilage 
of  the  first  rib  ;  action^  depresses  the  hyoid  bone  and  larynx, 
and  draws  them  backward  to  one  or  the  other  side  ;  nerves,  from 
the  loop  between  the  descendens  and  the  communicans  cervi- 
calis. 

Digastric'- 2;  origin,  has  two  fleshy  bellies  with  an  interme- 
diate rounded  tendon,  the  posterior'  is  attached  to  the  digas- 
tric groove  of  the  mastoid  process  of  the  temporal,  the  ante- 
rior^ to  the  depression  on  the  inner  side  of  the  lower  border  of 
the  jaw  near  the  symphysis ;  insertion,  tendon  perforates  the 
stylo-hyoid,  and  is  held  to  the  side  of  the  body  and  greater 
cornu  of  the  hyoid  bone  by  an  aponeurotic  loop  lined  with 
synovial  membrane ;  action,  raises  the  hyoid  bone ;  if  this  be 
fixed  by  its  muscles,  depresses  the  lower  jaw  ;  nerves,  posterior 
belly  by  the  facial,  anterior  by  the  mylo-hyoid  branch  of  the 
inferior  dental.  ^ 

Stylo-hyoid*:  origin,  middle  of  the  outer  surface  of  the  sty- 
loid process  of  the  temporal ;  insertion,  body  of  the  hyoid  at  its 
junction  with  the  greater  cornu  ;  it  is  perforated  by  the  digas- 
tric tendon;  action,  same  as  the  posterior  belly  of  the  digastric; 
nerve,  facial. 

Mylo-hyoid^:  onym,  mylo-hyoid  ridge  of  the  lower  jaw;  in- 
sertion, body  of  the  hyoid  bone  and  median  raphe;  action, 
same  as  the  digastric  and  stylo-hyoid  ;  nerve,  mylo-hyoid  branch 
of  the  inferior  dental ;  it  forms  with  its  fellow  the  muscular 
floor  of  the  mouth. 

Genio-hyoid''':  origin,  inferior  genial  tubercle  of  the  lower  jaw ; 
insertion,  body  of  the  hyoid  bone  ;  action,  same  as  the  digastric; 
nerve,  descendens  cervicalis. 

Genio-hyo-glossus^:  origin,  superior  genial  tubercle  of  the 
lower  jaw ;  insertion,  body  of  the  hyoid  bone,  side  of  the 
pharynx,  and  tongue  from  the  base  to  apex  ;  action,  protrudes 
the  tongue  by  the  posterior  and  inferior  fibers,  retracts  it  by  the 
anterior  fibers,  both  muscles  acting  render  tongue  concave  from 
side  to  side,  as  in  sucking  ;  nerve,  hypoglossal. 


148  ESSENTIALS  OF  HUMAN   ANATOMY. 

Hyo-glossus^:  oriyiii,  body,  lesser,  and  wliole  length  of  the 
greater  cornu  of  the  hyoid  bone  ;  insertion^  side  of  the  tongue ; 
the  parts  niay  be  called  /x/.s/o-,  choudrtf-^  and  licnifo-yhjusas ; 
action^  draws  down  the  sides  of  the  tongue,  making  it  convex  ; 
nerve ^  hypoglossal. 

Stylo-glossus ■* :  origin^  near  the  center  of  the  antero-external 
surface  of  the  styloid  process  and  stylo-maxillary  ligament ; 
insertion^  side  of  the  tongue  and  hyo-glossus  muscle ;  action., 
draws  the  tongue  upward  and  backward  ;  nerve.,  hypo- 
glossal. 

Lingualis  forms  the  bulk  of  the  tongue  lying  between  the 
hyo-glossus  and  genio-hyo-glossus  on  each  side  ;  it  has  four  sets 
of  fibers,  superior.,  inferior.,  transverse^  and  vertical  lingualis. 

Palatal  Region. 

Levator  palati:  origin^  under  surface  of  the  apex  of  the  pe- 
trous portion  of  the  temporal  bone  and  contiguous  portion  of  the 
cartilaginous  Eustachian  tube  ;  insertion.,  into  the  posterior  sur- 
face of  the  soft  palate ;  action,  elevates  the  soft  palate ;  nerve 
was  said  to  be  facial ;  it  is  probably  the  spinal  accessory  through 
the  pharyngeal  plexus. 

Tensor  palati:  origin.,  scaphoid  fossa,  outer  side  of  the  Eus- 
tachian tube,  spine  of  the  sphenoid,  edge  of  the  tympanic  plate  : 
insertion.,  after  reflection  around  the  hamular  process,  into  the 
forepart  of  the  aponeurosis  of  the  soft  palate  and  the  under 
surface  of  the  palate  bone;  action,  renders  the  soft  palate  tense; 
nerve,  branch  from  the  otic  ganglion. 

Azygos  uvulae:  origin,  posterior  nasal  spine  and  palatal  apo- 
neurosis ;  insertion,  uvula  ;  action,  raises  the  uvula  ;  nerve,  same 
as  for  the  levator  palati ;  it  is  not  a  single  muscle,  as  the  name 
implies. 

Palato-glossus  (anterior  pillar  of  fauces):  origin,  anterior  sur- 
face of  the  soft  palate  external  to  the  uvula ;  insertion,  side  and 
dorsum  of  the  tongue  ;  action,  as  one  of  its  names  implies,  con- 
strictor isthmi  faucium  ;  nerve,  spinal  accessory  through  the 
pharyngeal  plexus. 

Palato-pharyngeus  (posterior  pillar  of  fauces ) :  origin,  soft 
palate  ;  insertion,  posterior  border  of  the  thyroid  cartilage  and 
side  of  the  pharynx  ;  action,  closes  the  posterior  fauces;  nerve, 
same  as  for  the  palato-glossus. 


VERTEBRAL  REGION.  149 


Vertebral  Region. 

Rectus  capitis  anticus  major:  origui,  by  four  tendinous  slips 
from  the  anterior  tubercles  of  the  transverse  processes  of  the 
third,  fourth,  fifth,  and  sixth  cervical  vertebrae  ;  msertio)i,  bas- 
ilar process  of  the  occipital  bone;  action,  flexes  the  head  and 
slightly  rotates;  nerves,  suboccipital,  and  from  a  loop  formed 
by  it  and  the  second  cervical. 

Rectus  capitis  anticus  minor  :  origin,  front  of  the  lateral  mass 
of  the  atlas  and  root  of  its  transverse  process  ;  insertion,  basilar 
process  of  the  occipital  bone  behind  the  preceding  muscle  ;  ac- 
tion, flexes  the  head  ;  nerve,  suboccipital. 

Rectus  lateralis :  origin,  upper  surface  of  the  transverse 
process  of  the  atlas;  insertion,  jugular  process  of  the  occipital 
bone  ;  action,  draws  the  head  laterally  when  one  acts,  flexes 
when  both  act ;  nerve,  suboccipital.  These  muscles  belong  to 
the  series  of  intertransverse  muscles. 

Longus  colli:  origin,  superior  oblique  jjortion  from  the  ante- 
rior transverse  tubercles  of  the  third,  fourth,  and  fifth  cervical 
vertebrae  ;  insertion,  tubercle  on  the  anterior  arch  of  the  atlas  ; 
the  inferior  oblique  portion  arises  from  the  bodies  of  the  first  two 
or  three  thoracic  vertebrae,  insertion,  transverse  processes  of 
the  fifth  and  sixth  cervical  vertebrae  ;  vertical  portion  extends 
between  the  bodies  of  the  three  upper  thoracic  and  three  lower 
cervical,  and  those  of  the  second,  third,  and  fourth  cervical 
vertebrae ;  action,  flexes  and  slightly  rotates  the  cervical 
spine ;  nerves,  anterior  branches  from  the  lower  cervical 
nerves. 

Scalenus  anticus'"  (Fig.  87)  :  origin,  anterior  tubercles  of  the 
transverse  processes  of  the  third,  fourth,  fifth,  and  sixth  cer- 
vical vertebrae  ;  insertion,  tubercle  on  the  upper  surface  of  the 
first  rib;  action,  lateral  flexion  of  the  cervical  spine  or  eleva- 
tion of  the  ribs  ;  nerves,  anterior  branches  of  the  fourth,  fifth, 
and  sixth  cervical  nerves  before  the  plexus  is  made. 

Scalenus  medius  ^'  :  origin,  posterior  tubercles  of  the  trans- 
verse processes  of  the  six  lower  cervical  vertebne  ;  insertion, 
upper  surface  of  the  first  rib  behind  the;  subclavian  groove  ; 
«c;/Vy/?,  similar  to  the  preceding;  nerves,  anteri(»r  branches  from 
the  cervical. 

Scalenus  posticus  :  origin,  posterior  tubercles  of  the  two  or 
three  lower  cervical   vertebrae  ;   insertion,  outer  surface  of  the 


150  ESSENTIALS  OF  HUMAN  ANATOMY. 

second  rib ;  action,  flexes  neck  laterally,  or  elevates  the  second 
rib ;  nerves,  anterior  branches  from  the  three  lower  cervical. 

Muscles  of  the  Back. 

first  layer  (Fig.  88): 

Trapezius  '  :  origin,  inner  third  of  the  superior  curved  line  of 
the  occipital  bone,  ligamentum  nuchas,  spinous  processes  of  the 
seventh  cervical  and  of  all  the  thoracic  vertebrae,  and  correspond- 
ing portion  of  the  supraspinous  ligament ;  insertion,  outer  third 
of  the  posterior  border  and  upper  surface  of  the  clavicle,  inner 
margin  of  the  acromion  process,  the  superior  lip  of  the  crest  of 
the  spine  of  scapula,  and  the  tubercle  at  its  inner  extremity  ; 
action,  one  acting  draws  the  head  to  its  own  side,  both  acting  draw 
the  head  backward,  and  with  the  head  fixed  elevate  the  point 
of  the  shoulder ;  middle  and  lower  fibers  partially  rotate  the 
scapula  on  the  chest ;  nerves,  spinal  accessory,  third  and  fourth 
cervical  from  anterior  divisions. 

Ligamentum  nuclise  (a  thin  band  of  condensed  cellulo-fibrous 
membrane):  c»r/^/«,  external  occipital  protuberance;  insertion, 
spinous  processes  of  all  the  cervical  vertebrae  except  the  atlas ; 
a  rudiment  of  a  strong  elastic  ligament  sustaining  the  head  in 
the  lower  animals. 

Latissimus  dorsi* :  origin,  by  an  aponeurosis  from  the  spinous 
processes  of  the  six  lower  thoracic  vertebras,  those  of  the  lumbar 
and  sacral  vertebras  and  supraspinous  ligament,  also  external  lip 
of  the  iliac  crest  behind  the  external  oblique,  from  the  three  or 
four  lower  ribs,  and  often  from  the  inferior  angle  of  the 
scapula  ;  insertion,  floor  of  the  bicipital  groove  of  the  humerus  ; 
action,  draws  the  humerus  downward  and  backward  while 
rotating  inward  ;  with  fixed  arms,  raises  the  lower  ribs  in 
forcible  inspiration,  assists  the  greater  pectorals  and  the  ab- 
dominal muscles  in  drawing  the  trunk  forward,  as  when  climb- 
ing, or  using  crutches,  etc.  ;  nerve,  long  subscapular  nerve. 

Second  layer: 

Levator  scapulae  '° :  origin,  by  three  or  four  tendinous  slips 
from  the  posterior  tubercles  of  the  transverse  processes  of  the 
three  or  four  upper  cervical  vertebrae  ;  insertion,  posterior  bor- 
der of  the  scapula  between  the  superior  angle  and  triangular 
surface  at  the  apex  of  the  spine ;  action,  raises  the  scapular 


MUSCLES  OF  THE   BACK.  151 

angle,  extensor  and  lateral  flexor  of  the  neck  ;   nerves,  from  the 
anterior  divisions  of  the  third,  fourth,  and  fifth  cervical. 

Rhomboideus  minor  "  :  origin,  ligamentuni  nuchte,  and  spinous 
processes  of  the  seventh  cervical  and  first  thoracic  vertebrae ; 


Fig.  88.— Muscles  of  the  back  (Leidy). 

insertion,  margin  of  the  triangular  surface  at  the  apex  of  the 
spine  of  the  scapula  ;  act  ion,  draws  the  inferior  angle  back- 
ward and   upward  ;   nerve,  fifth   cervical. 

Rhomboideus  major ''^ :  origin,  spinous  processes  of  the  four  or 


152  ESSENTIALS  OP  HUMAN   ANATOMY. 

five  upper  thoracic  vertebrtnc  and  supraspinous  ligament ;  inser- 
tion, tendinous  arch  stretched  from  the  triangular  surface  at 
the  apex  of  the  spine  of  the  scapula  to  the  inferior  angle,  the 
arch  being  connected  with  the  vertebral  border  by  a  thin 
membrane ;  action,  draws  the  inferior  angle  backward  and 
upward ;    nerve,  fifth  cervical. 

Third  layer: 

Serratus  posticus  superior :  origin^  by  a  thin  aponeurosis  from 
the  ligamentum  nuchae  and  spinous  processes  of  the  seventh 
cervical  and  two  or  three  upper  thoracic  vcrtebme  and  the 
supraspinous  ligament;  insfrrtion,  by  fleshy  digitations  into  the 
upper  borders  of  the  second,  third,  fourth,  and  fifth  ribs  a  lit- 
tle beyond  their  angles  ;  action,  elevates  the  ribs  during  in- 
spiration ;  nerves,  branches  of  the  upper  intercostals. 

Serratus  posticus  inferior"':  origin,  by  a  thin  aponeurosis 
from  the  spinous  processes  of  the  two  last  thoracic  and  two 
or  three  upper  lumbar  vertebme  and  supraspinous  ligament ; 
insertion,  by  four  digitations  into  the  lower  borders  of  the  four 
lower  ribs,  beyond  their  angles ;  except  the  last  rib,  which  has 
no  angle ;  action,  depresses  the  ribs  in  expiration ;  nerves, 
branches  of  the  lower  intercostal  nerves. 

Splenius  capitis  et  colli  ^^'  ^* :  origin,  tendinous  from  the  lower 
half  of  the  ligamentum  nuchae,  the  spinous  processes  of  the 
last  cervical  and  of  the  six  upper  thoracic  vertebrae,  and  supra- 
spinous ligament;  insertion  (S.  capitis^^),  mastoid  process  and 
rough  surface  beneath  the  superior  curved  line  of  the  occipital 
bone  ;  (S.  colli^*),  posterior  tubercles  of  the  transverse  processes 
of  the  two  or  three  upper  cervical  vertebrae  ;  action,  together, 
draw  the  head  directly  backward,  singly,  flex  the  head  laterally 
and  slightly  rotate  it  to  the  same  side  ;  nerves,  external  poste- 
rior branches  of  the  spinal  nerves,  the  cervical  and  thoracic. 

Fourth  layer : 

Erector  spinas  '•  '■  ^'  *■  ^'  '^  (Fig.  89)  :  origin,  the  sacro-iliac 
groove,  the  anterior  surface  of  the  lumbo-sacral  tendon,  which 
is  attached  internally  to  the  spines  of  the  sacrum,  the  spinous 
processes  of  the  lumbar  and  three  lower  thoracic  vertebrae  and 
supraspinous  ligament  externally,  the  back  part  of  the  inner  lip 
of  the  iliac  crest,  with   the  rudimentary  transverse  processes 


MUSCLES  OF  THE  BACK. 


153 


of  the  sacrum  and  great  sacro-sciatic  ligament;  this  muscle  oppo- 
site the  last  rib  divides  into  the  ilio-costalis  and  longissiraus 
dorsi  muscles ;  action,  maintains  the  spine  erect  and  bends  the 
body  backward ;  nerves,  external  posterior  branches  of  the 
lumbar  and  thoracic  nerves. 

Ilio-costalis ''  - :  origin,  is  part  of  the  erector  spina? ;  insertion,  by 
six  or  seven  tendons  into  the  angles  of  the  sixth  to  the  eleventh 
and  border  of  the  twelfth  ribs ; 
action,  same  as  the  erector  spinae; 
nerves,  same  as  the  erector  spinge. 

Musculus  accessorius  ad  ilio-cos- 
talem  :  origin,  by  flattened  tendons 
from  angles  of  the  seventh  to  the 
eleventh  and  back  of  the  last  rib ; 
insertion,  angles  of  the  six  upper 
ribs ;  action  and  nerves,  same  as  the 
erector  spinas. 

Cervicalis  ascendens:  orv^i??, backs 
of  four  or  five  upper  ribs ;  insertion, 
posterior  tubercles  of  the  trans- 
verse processes  of  the  fourth, 
fifth,  and  sixth  cervical  vertebrae  ; 
action,  keeps  the  neck  erect ; 
nerves,  external  posterior  branches 
of  the  cervical  and  thoracic  nerves. 

Longissimus  dorsi ^:  origin,  is 
part  of  the  erector  spinae ;  inser- 
tion, posterior  surface  of  the  lum- 
bar transverse  processes  and  ac- 
cessory tubercles  of  articular  proc- 
esses, tips  of  transverse  processes 
of  all  the  thoracic  vertebras,  and 
from  the  nine  to  the  ten  lowest  ribs 
between  their  tuberosities  and  an- 
gles; action  and  nerves,  same  as 
the  erector  sy»in;ie. 

Transversalis  colli'*'-':  o/vV////,  ten- 
dinous from  the  summits  of  the  .  ,    .     , 

, ,  .     ,  Fio.  89.— Muscles  of  the  back, 

Six  upper  thoracic  transverse  pro-  deep  layers  (Leidy). 

cesses ;  insertion,  posterior  tuber- 
cles of  the  transverse  processes  from   the  second  to  the  sixth 


154  ESSENTIALS  OF  HUMAN   ANATOMY. 

cervical  vertebra) ;  action^  keeps  the  neck  erect ;  nerves^  exter- 
nal posterior  branches  of  the  cervical  and  thoracic  nerves. 

Trachelo-mastoid ' :  origin.,  by  tendons  from  the  transverse  proc- 
esses of  the  third,  fourth,  fifth,  and  sixth  thoracic  vertebra3  and 
articular  processes  of  the  three  or  four  lower  cervical ;  tuserfiou, 
posterior  margin  of  the  mastoid  process  ;  action,  flexes  the  head 
laterally  ;  nerves,  external  posterior  branches  of  the  cervical  and 
thoracic  nerves. 

Spinalis  dorsi:  origin,  by  tendons  from  the  spinous  proc- 
esses of  the  two  last  thoracic  and  the  first  two  lumbar  ver- 
tebrae ;  insertion,  by  separate  tendons  into  the  spinous  proc- 
esses of  from  four  to  eight  thoracic  vertebrae ;  action,  erects 
the  spine ;  nerves,  external  posterior  branches  of  the  thoracic 
nerves. 

Spinalis  colli:  origin,  fifth,  sixth,  and  seventh  cervical  spinous 
processes,  also  sometimes  those  of  the  first  and  second  thoracic 
(this  muscle  is  sometimes  absent);  insertion,  spinous  process 
of  the  axis,  occasionally  those  of  the  two  vertebra3  below ; 
action,  extends  the  cervical  spine ;  nerves,  external  posterior 
branches  of  the  cervical  nerves. 

Complexus^:  origin,  by  tendons  from  the  tips  of  the  transverse 
processes  oi  the  six  or  seven  upper  thoracic  and  seventh  cervical 
vertebras,  and  articular  processes  of  the  three  cervical  vertebrae 
above  this  ;  insertion,  internally  between  the  curved  lines  of  the 
occipital  bone  ;  action,  both  draw  the  head  backward,  singly, 
lateral  flexion  with  rotation  turning  the  face  to  the  opposite 
side  ;  nerves,  internal  posterior  branches  of  the  cervical,  sub- 
occipital, and  great  occipital  (the  hiventer  cervicis,  being  usu- 
ally blended  with  this  muscle  on  its  inner  side,  will  receive  no 
separate  description). 

Fifth  layer: 

Semispinalis  dorsi ^°:  origin,  by  small  tendons  from  the  trans- 
verse processes  of  the  thoracic  vertebrae,  from  the  sixth  to  the 
tenth  inclusive;  insertion,  by  five  or  six  tendons,  into  the  spi- 
nous processes  of  the  four  upper  thoracic  and  two  lower  cervical 
vertebrae ;  action,  erects  the  spinal  column ;  nerves,  internal 
posterior  branches  of  the  thoracic  nerves. 

Semispinalis  colli"  :  origin,  tendinous  and  fleshy  from  the  five 
or  six  upper  thoracic  transverse  processes ;  insertion,  second, 
third,  fourth,  and  fifth  cervical  spinous  processes,  the  highest 


MUSCLES  OF  THE   BACK.  155 

being  the  thickest ;  action,  erects  the  cervical  spine  ;  nerves^  in- 
ternal posterior  branches  of  the  cervical  nerves. 

Multifldus  spinse  "' :  ur'ujiii^  back  of  the  sacrum,  aponeurosis  of 
the  erector  spinas  (sacral  region) ;  posterior  superior  iliac  spine, 
posterior  sacro-iliac  ligaments  (sacro-iliac  region) ;  mammil- 
lary  processes  (lumbar  region)  ;  transverse  processes  (thoracic 
region)  ;  articular  processes  (four  lower  cervical  vertebrae)  ;  in- 
sertion^ spinous  process  of  the  third  or  fourth  vertebra  above 
(most  superficial),  second  or  third  above  (middle  layer)  ;  two 
contiguous  vertebrae  (deepest  layer)  ;  it  extends  i'rom  the  last 
lumbar  to  the  axis ;  keeps  the  spine  erect  and  rotates  it ;  nerves, 
internal  posterior  branches  of  the  cervical,  thoracic,  lumbar,  and 
sacral  nerves. 

Rotatores  spinas  (eleven  pairs  in  the  thoracic  region  only)  : 
origin  each  from  the  upper  back  part  of  the  transverse  proc- 
ess ;  insertion,  lower  outer  part  of  the  lamina  of  the  vertebra 
above ;  action,  as  name  implies ;  nerves,  internal  posterior 
thoracic  branches. 

Interspinales :  origin,  variable  in  number,  there  are  usually  six 
cervical  pairs  commencing  between  the  apices  of  the  second  and 
third  spinous  processes  ;  two,  occasionally  three  thoracic  pairs, 
between  the  first  and  second,  eleventh  and  twelfth,  sometimes 
second  and  third  vertebrae ;  four  lumbar  pairs ;  sometimes  a 
pair  between  the  last  thoracic  and  the  first  lumbar,  and  the  fifth 
lumbar  and  sacrum;  (yc/ />>/?,  extend  the  spine  ;  nerves,  internal 
posterior  nerves  of  the  regions. 

Extensor  coccygis  is  rarely  found  :  origin,  last  bone  of  the 
sacrum,  or  first  of  the  coccyx  ;  insertion,  lower  part  of  the 
coccyx,  behind  ;  action,  as  named  ;  nerves,  posterior  divisions 
of  tlie  fourth  and  fifth  sacral  and  coccygeal. 

Intertransversales''' :  origin  and  insertion,  double  muscles  be- 
tween the  anterior  and  the  posterior  tubercles  of  the  trans- 
verse processes  in  the  cervical,  occupy  the  intertransverse 
spaces  in  other  regions  (three  or  four  thoracic  and  four  lum- 
bar) ;  action,  lateral  flexion  singly,  steady  spine  when  both 
sidi's  act;  verves,  posterior  spinal  branches  of  each   region. 

Rectus  capitis  posticus  major'':  origin,  spinous  process  of  the 
axis;  insertion,  inferior  curved  line  of  the  occipital  bone  and 
the  surface  below  ;  rotates  and  extends  the  head  ;  nerve,  sub- 
occipital. 

Rectus  capitis  posticus  minor ''^:   origin,  tub(!rcle  on  the  poste- 


15(5  ESSENTIALS  OF  HUMAN    ANATOMY. 

rior  arch  of  the  atlas;  insertiou,  rouuli  .surface  beneath  the  in- 
ferior curved  line,  internal  to  the  major,  nearly  as  far  as  the 
foramen  maunum  ;  <ictio}i^  extends  the  head  ;  nerce,  suboccipi- 
tal. 

Obliquus  capitis  inferior''^:  origin^  apex  of  the  spinous  process 
of  the  axis  ;  uis(  rtion^  lower  and  back  part  of  the  transverse 
process  of  the  atlas;  action^  rotates  the  atlas  and  head;  nerve., 
suboccipital. 

Obliquus  capitis  superior'^:  origin^  tendinous  from  the  upper 
part  of  the  transverse  process  of  the  atlas;  insert  ion.,  between 
the  curved  lines  of  the  occipital  bone  external  to  the  com- 
plexus  ;  action.,  extends  the  head,  flexes  laterally  ;  nerve,  sub- 
occipital. 

Muscles  of  the  Abdomen. 

External  oblique'''  (Fig.  DO)  :  origin,  by  eight  fleshy  digitations 
from  the  external  surface  and  lower  borders  of  the  eight  infe- 
rior ribs;  in.sertion,  anterior  half  of  the  outer  lip  of  the  iliac 
crest,  by  an  aponeurosis  joining  its  fellow  of  the  opposite  side 
it  forms  the  lined  alba,  a  median  tendinous  raphe,  connected 
above  with  the  ensiform  cartilage,  below  with  the  symphysis 
pubis ;  this  aponeurosis  is  continuous  above  with  the  aponeu- 
rosis of  the  pectoralis  major,  below  it  forms  a  broad  infolded 
band,  continuous  with  the  fascia  lata,  stretching  from  the  an- 
terior iliac  spine  to  the  pubic  spine — /.  e.  Ponpart's  ligament — 
reflected  from  which,  into  the  pectineal  line,  is  a  portion  called 
Ginihernaf's  ligamenf ;  above  the  crest  of  the  os  pubis  is  the  tri- 
angular external  abdominal  ring,  its  external  border  being  Pou- 
part's  ligament,  its  inner,  aponeurotic  fibers,  both  called  piUars 
of  the  ring ;  action,  compresses  the  viscera,  flexes  the  thorax  on 
the  pelvis,  or  flexes  the  pelvis  on  the  thorax,  according  to  which 
is  the  fixed  point,  also  assists  expiration  ;  nerves,  lower  inter- 
cost  als. 

Internal  oblique'^:  origin,  fleshy  from  the  outer  half  of  Pou- 
part's  ligament,  anterior  two-thirds  of  the  middle  lip  of  the  iliac 
crest,  and  posterior  lamella  of  the  lumbar  fascia  ;  insertion,  crest 
and  pectineal  line  of  the  os  pubis  with  the  transversalis  muscle  — 
forming  the  conjoined  tendon,  a  part  of  the  posterior  boundary 
of  the  external  abdominal  ring — cartilages  of  the  three  lower 
ribs,  and  by  an  aponeurosis,  which  splits  for  its  upper  three- 
fourths  to  enclose  the  rectus  muscle,  into  the  linca  alba  ;  the 


MUSCLES  OF  THE   ABDOMEN. 


1 


0( 


anterior  layer  blends  with  the  aponeurosis  of  the  external  ob- 
lique, the  posterior  with  that  of  the  transversalis  muscle,  the 
undivided  lower  fourth  passing  in  irout  of  the  rectus;  action, 


Fig.  WJ.— Muscles  of  the  thorax  and  the  abdomen  (Leidy). 

same  as  the  external   oblique  ;  nerves,  lower  intercostals,  ilio- 
hypof^astrir*.  arxl  ilio-in<ininal. 

Transversalis  :  oriyin,  fleshy  from  the  outer  third  of  I'oupart's 
li^amerjt,  anterior  three-fourths  of  the  inner  lip  of  the  iliac  crest, 
inn(!r  surface;  of  the  six  lower  costal  cartilages,  and  by  a  broad 
apoiHMirosis,  the  InnilKtr  J'dscin.  from  the  lumbar  transverse  proc- 


158  ESSENTIALS  OF  HUMAN   ANATOMY. 

esses ;  inscrfion,  with  the  internal  oblique  as  the  conjoined  tendon 
into  the  pubic  crest  and  pectineal  line,  by  its  aponeurosis  into 
the  linea  alba,  the  upper  three-fourths  passing  behind,  the  rectus 
abdominis,  the  remainder  in  front  of  that  muscle  ;  fiction  and 
nerves  similar  to  the  internal  oblique. 

Lumbar  fascia  :  the  vertebral  aponeurosis  of  the  transversalis 
divides  into  an  anterior  thin  layer  attached  to  the  front  of  the 
lumbar  transverse  processes  and  to  the  lower  margin  of  the  last 
rib,  thus  forming  the  ligeunentiim  arcuatum  cxferniun  ;  a  middle, 
stronger  layer,  attached  to  the  apices  of  the  transverse  proc- 
esses ;  and  a  posterior  layer  attached  to  the  apices  of  the 
spinous  processes ;  the  quadratus  lumborum  lies  between  the 
anterior  and  the  middle  layers,  the  erector  spinas  between  the 
middle  and  the  posterior ;  the  latter  receives  the  attachment  of 
the  internal  oblique,  and  blended  with  the  aponeuroses  of  the 
serratus  posticus  inferior  and  latissimus  dorsi  forms  the  lumbar 
fascia,  consisting  of  three  layers. 

Rectus  abdominis'^:  origin,  hy  ivio  tendons  from  the  pubic 
crest  and  ligaments  over  the  symphysis  pubis  ;  insertion,  carti- 
lages of  the  fifth,  sixth,  and  seventh  ribs;  this  muscle  is 
enclosed  in  a  sheath,  the  upper  three-fourths  in  front  formed 
by  the  aponeurosis  of  the  external  oblique  and  half  of  that  of 
the  internal  oblique,  behind  for  the  same  extent  the  trans- 
versalis aponeurosis  with  the  posterior  division  of  that  of  the 
internal  oblique ;  at  the  lower  fourth  the  aponeuroses  of  all 
three  muscles  pass  in  fremt  of  the  rectus  ;  three  or  four  tendi- 
nous intersections  traverse  the  muscle  called  the  linese  trans- 
versa, while  the  Iine?e  semiJunares.  two  curved  tendinous  lines 
corresponding  to  the  outer  border  of  the  recti  muscles,  extend 
on  either  side  from  the  eighth  costal  cartilage  to  the  pubes ; 
action,  flexes  the  thorax  on  the  pelvis,  and  vic^j  versa,  also  com- 
presses the  abdominal  viscera  ;  nerves  are  the  lower  intercostals 
and  perhaps  the  ilio-hypogastrie. 

Pyramidalis  :  origin,  from  front  of  the  pubic  crest  and  anterior 
pubic  ligament,  lying  in  front  of,  but  in  same  sheath  with  the 
rectus  ;  insertion,  linea  alba  midway  between  the  pubes  and  the 
umbilicus  ;  action,  a  tensor  of  the  linea  alba  ;  nerves,  two  lower 
intercostals  and  sometimes  the  ilio-hypogastric. 

Quadratus  lumborum'^  (Fig.  89)  :  origin,  ilio-lumbar  ligament, 
adjacent  two  inches  of  the  iliac  crest,  and  upper  borders  of  the 
transverse  processes  of  the  three  or  four  lower  lumbar  vertebrae  ; 


MUSCLES  OF  THE  THORAX.  150 

insertion,  one-half  of*  the  lower  border  of  the  last  rib,  apices  of 
the  transverse  processes  of  the  four  upper  lumbar  vertebrae  ; 
action,  flexes  the  trunk — both  acting  :  flexes  laterally — one 
acting;  depresses  the  ribs  with  fixed  pelvis  and  is  then  an  ex- 
piratory muscle,  but  by  fixing  the  last  rib  and  opposing  the 
diaphragm  it  is  an  assisfrfjit  to  inf>pir<itioa ;  neny^s,  anterior 
branches  of  the  last  thoracic  and  upper  lumbar. 

Muscles  of  the  Thorax. 

External  intercostals '  ^  (Fig.  90)  (eleven  pairs):  origin,  each 
from  the  outer  lip  of  the  groove  on  the  lower  border  of  each 
rib  from  the  tuberosity  to  the  costal  cartilage  ;  iuHcrtion,  pass 
obliquely  downward  and  forward  to  the  upper  border  of  the 
rib  below  for  same  distance ;  action,  raise  and  evert  the  ribs  in 
inspiration  ;   nerves  for  each  group  are  the  intercostals. 

Internal  intercostals  (eleven  pairs)  :  origin,  each  from  the 
inner  lip  of  the  groove  on  the  lower  border  of  the  rib  reaching 
from  the  angle  to  the  sternum  ;  insertion,  passing  downward 
and  backward  to  the  upper  border  of  the  rib  below ;  action, 
depress  and  invert  the  ribs  in  expiration ;  probably  the  two 
sets  of  interco.stals  act  together  in  inspiration  and  in  expiration, 
depending  upon  a  fixed  point  above  or  below. 

Infracostales  or  subcostales  are  placed  posteriorly  where  the 
internal  intercostals  cease;  they  vary  in  number,  and  are  most 
common  between  the  lower  ribs  ;  origin,  from  the  inner  surface 
of  one  rib ;  insertion,  inner  surface  of  the  first,  second,  or  third 
rib  below,  passing  obliquely  downward  and  backward  ;  action, 
same  as  the  internal  intercostals;  nerves,  intercostals. 

Triangularis  sterni :  origin,  lower  part  of  the  side  of  the  ster- 
num, inner  surface  of  the  ensiform  cartilage,  and  sternal  ends 
of  the  co.stal  cartilages  of  the  two  or  three  lower  true  ribs;  in- 
sertion, by  fleshy  digitations  into  the  lower  border  and  inner 
surfaces  of  the  costal  cartilages  of  the  second  to  the  sixth 
ribs  inclusive;  action,  draws  down  the  costal  cartilages  in  ex- 
piration ;  nerves,  intercostals. 

Levatores  costarum :  origin  ftw(;lve  pairs),  extremities  of 
seventh  cervical  and  eleven  upper  thoracic  transverse  proces.ses  ; 
insertion,  rough  surface  between  the  tuberosity  and  angle  of  the 
rib  b(;low  ;  action,  assist  the  external  intercostals  in  raising 
the  ribs  in  in.spiration ;  nerves,  intercostals. 


160 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Diapliragm  (Fig.  91)  :  oriyin.  arched  and  convex  toward  the 
chest,  from  the  ensiform  cartilage  in  front,  on  either  side,  inner 
surfaces  of  the  cartilages  and  bony  portions  of  the  six  or  seven 
lower  ribs,  behind,  from  the  ligamentum  arciiatum  externum  ^ 
and  internum ",  and  by  its  crura  *,  ^,  the  left  from  bodies  of  the 
two  upper,  the  right,  from  those  of  the  three  or  four  upper 
lumbar  vertebrae;  iuscrfion,  into  the  central  cordiform  ten- 
don \  '",  '^ ;  action,  chief  respiratory  muscle,  increasing  capacity 
of  the  chest  by  becoming  flattened  when  contracted  ;  also  aids 
all  eff"orts  of  expulsion  ;  nerves,  two  phrenics  and  phrenic 
plexuses  of  the  sympathetic. 


Fig.  91.— The  diaphragm,  inferior  surface  (Leidy). 

Openings  of  the  diaphragm:  the  aortic^,  median,  in  front  of 
the  vertebral  bodies — really  behind  the  diaphragm — for  the 
aorta,  vena  azygos  major,  thoracic  duct,  sometimes  the  left 
sympathetic  nerve  ;  the  esophageal^,  elliptical,  muscular, 
formed  by  the  crura,  for  the  esophagus  and  pneumogastric 
nerves;  the  opening  for  the  vena  cava^*^,  highest,  quadrilateral 
bounded  by  four  tendinous  bundles  meeting  at  right  angles  ; 
the  right  eriis^  transmits  the  sympathetic,  greater  and  lesser 
splanchnic  nerves  ;  the  fe/f  cms  *  the  left  greater  and  lesser 
splanchnic  nerves  and  the  vena  azygos  minor. 


MUSCLES  OF  THE  SHOULDER  AND  ARM.         161 


Muscles  of  the  Shoulder  and  Arm. 

Pectoralis  major  ^  (Fig.  90):  origin,  anterior  surface  of  the 
inner  half  of  the  clavicle,  half  the  breadth  of  the  anterior  sur- 
face of  the  sternum  as  low  as  the  sixth  or  seventh  cartilage,  from 
the  front  of  the  second  to  the  sixth  cartilage,  from  the  sixth 
rib,  and  from  the  aponeurosis  of  the  external  oblique  ;  in- 
sertion, fibers  converge  and  overlap,  the  lower  being  folded 
back  upon  themselves,  to  be  attached  by  a  flat  tendon  to  the 
anterior  lip  of  the  bicipital  groove  of  the  humerus ;  action, 
draws  the  arm  forward  and  inward  ;  with  fixed  arm,  an  acces- 
sory muscle  of  forced  inspiration  ;  nerves,  two  anterior  thoracics. 

Pectoralis  minor  ^  (Fig.  90)  :  origin,  tendinous  from  the  upper 
margin  and  the  outer  surface  of  the  third,  fourth,  and  fifth  ribs 
near  the  cartilages,  often  from  the  second,  and  aponeurosis  over 
the  intercostal  muscles ;  insertion,  inner  border  and  upper  sur- 
face of  the  coracoid  process  of  the  scapula  ;  action,  depresses  the 
point  of  the  shoulder,  elevates  the  ribs  during  inspiration  when 
the  scapula  is  fixed  ;  nerve,  internal  anterior  thoracic. 

Subclavius  ^ :  origin,  tendinous  from  the  first  costal  cartilage 
and  rib  ;  insertion,  groove  on  the  middle  third  of  the  under  sur- 
face of  the  clavicle ;  action,  draws  the  clavicle  down  and  in, 
steadies  the  sterno-clavicular  articulation  ;  nerve,  branch  from 
the  trunk  formed  by  the  fifth  and  sixth  cervical. 

Serratus  magnus  *  (Fig.  90)  :  origin,  by  nine  fleshy  digitations 
from  the  outer  surface  and  upper  border  of  the  eight  upper 
ribs  (second  rib  has  two)  and  aponeurosis  covering  the  upper 
intercostal  spaces ;  insertion,  whole  length  of  the  anterior 
aspect  of  the  posterior  border  of  the  scapula  ;  action,  carries  the 
scapula  forward  and  is  used  in  pushing,  also  raises  the  point  of 
the  shoulder  by  rotating  the  bone  on  the  chest-wall ;  nerve, 
posterior  thoracic. 

Deltoid  -  (Fig.  90)  :  origin,  outer  third  of  the  anterior  border 
and  upper  surface  of  the  clavicle,  outer  margin  and  upper  sur- 
face of  the  acromion  process,  and  the  whole  length  of  the  lower 
border  of  the  spine  of  the  scapula  ;  insertion,  tendinous  into 
the  rough  prominence  on  the  middle  of  the  outer  side  of  the 
shaft  of  the  humerus  ;  action,  raises  the  arm  to  a  right  angle, 
also  draws  it  forward  by  the  anterior  fibers,  or  slightly  back- 
ward by  the  posterior  portion;  nerve,  circumflex. 

Subscapularis  *  (Fig.  92)  :  origin,  inner  two-thirds  of  the  sub- 
U 


162 


ESSENTIALS  OF  HUMAN    ANATOMY. 


scapular  fossa;  msertt'on,  lesser  tuberosity  and  neck  of  the 
humerus;  action,  rotates  the  humerus  inward  and  adducts  ; 
)ierves,  upper  and  lower  subscapular. 

Supraspinatus  ^'  (Fig.  88):  origin,  internal  two-thirds  of  the 
supraspinous  fossa  and  the  fascia  covering  it ;  insertion^  highest 
facet  on  the  greater  tuberosity  of  the  humerus  ;  action,  assists 
the  deltoid,  fixes  the  head  of  the  humerus  in  its  socket ;  nerve, 
suprascapular. 

Infraspinatus  **  (Fig.  88)  :  origin,  internal  two-thirds  of  the 
infraspinous  fossa  ;  insertion,  tendinous,  middle  facet  of  the 
greater  tuberosity  of  the  humerus  ;  action,  rotates  the  humerus 
outward,  acts  with  neighboring  tendons  as  a  ligament  of  the 
shoulder-joint ;   nerve,  suprascapular. 

Teres  minor  ^^  (Fig.  88)  :  origin,  upper  two-thirds  of  the  dor- 
sal surface  near  the  axillary  border  of 
the  scapula  and  intermuscular  septa ;  in- 
sertion, lowest  facet  on  the  greater  tuber- 
osity of  the  humerus  and  a  small  surface 
of  the  shaft  below  ;  action,  rotates  the 
humerus  outward  ;  nerve,  circumflex. 

Teres  major"-*'  (Fig.  88):  origin,  lower 
third  of  the  external  border  of  the  infra- 
spinous fossa  and  intermuscular  septa 
between  it  and  the  teres  minor  and  in- 
fraspinatus ;  insertion,  internal  lip  of  the 
bicipital  groove ;  action,  draws  the  hu- 
merus downward  and  backward  when 
raised,  also  rotates  it  inward ;  nerve, 
lower  subscapular. 

Coraco-bracliialis  ^  (Fig.  92) :  origin, 
fleshy  from  the  apex  of  the  coracoid  proc- 
ess of  the  scapula ;  insertion,  into  the 
rough  ridge  at  the  middle  of  the  inner 
border  and  surface  of  the  humerus  ;  ac- 
tion, draws  the  humerus  forward  and 
inward,  also  elevates  it  ;  nerve,  special 
branch  from  the  outer  cord  of  the  brachial 
plexus  from  the  seventh  cervical. 

Biceps  flexor  cubiti  ^  (Fig-  92):  origin, 
short  head,  tendinous,  in  common  with  the  coraco-brachialis 
from  the  tip  of  the  coracoid  process  of  the  scapula,  long  head, 


Fig.  92.— Anterior  hum- 
eral region  (Leidy). 


MUSCLES  OF  THE  FOREARM.  163 

upper  margin  of  the  glenoid  cavity  by  a  rounded  tendon 
continuous  with  the  glenoid  ligament ;  insertion^  tendinous  into 
the  back  part  of  the  tuberosity  of  the  radius  (a  bursa  is  inter- 
posed in  front),  and  by  a  broad  aponeurosis  opposite  the  elbow, 
into  the  fascia  of  the  forearm  ;  action^  supinates  and  flexes  the 
forearm,  renders  the  forearm  fascia  tense  ;  nerve,  musculo-cuta- 
neous. 

BracMalis  anticus  " :  origin,  lower  half  of  the  outer  and  inner 
surfaces  of  the  shaft  of  the  humerus,  embracing  the  insertion 
of  the  deltoid  ;  insertion,  tendinous  into  the  inferior  surface  of 
the  coronoid  process  of  the  ulna;  action,  flexes  the  forearm; 
nerves,  musculo-cutaneous  and  musculo-spiral. 

Triceps  extensor  cubiti  ^^ :  origin,  scapular  or  Jong  head  from 
the  rough  triangular  depression  below  the  glenoid  fossa,  the 
external  head  from  the  posterior  surface  of  the  shaft  between 
the  upper  part  of  the  spiral  groove  and  the  insertion  of  the 
teres  minor,  the  internal  head  from  the  posterior  surface  below 
the  spiral  groove  ;  insertion,  tendinous,  back  part  of  the  upper  ■ 
surface  of  the  olecranon  process  of  the  ulna ;  action,  extends 
the  forearm  and  arm  ;  nerve,  musculo-spiral. 

Subanconeus  :  origin,  humerus  above  the  olecranon  fossa  ;  in- 
sertion, posterior  ligament  of  the  elbow  ;  action,  prevents  the 
loose  capsule  from  being  pinched  during  extension ;  nerve, 
musculo-spiral. 

Muscles  of  the  Forearm. 

Anterior,  or  flexor  and  pronator  group  :  All  take  origin  from 
the  internal  epicondyle,  except  the  deep  layer. 

Superficial  layer. 

Pronator  teres  ^  (Fig.  93) :  origin,  double,  above  from  the  in- 
ternal supracondylar  ridge  and  common  tendon,  fascia  of  the 
forearm  and  intermuscular  septum,  below  from  the  inner  side  of 
the  coronoid  process  of  the  ulna  ;  insertion,  tendinous  into  the 
oblique  line  and  rough  ridge  on  the  middle  of  the  outer  surface 
of  the  shaft  of  the  radius ;  action,  pronates  the  forearm  and 
aids  flexion  ;  nerve,  median. 

Flexor  carpi  radialis  ^ :  origin,  internal  epicondyle  by  the 
common  tendon,  forearm  fascia,  and  intermuscular  septa;  in- 
sertion, tendinous,  into  the  base  of  the  index  metacarpal  bone 
and  usually  of  the  third  ;  action,  flexes  the  wrist,  then  the 
forearm  ;  also  pronates  the  forearm  ;  nerve,  median. 


164 


ESSENTIALS  OF   HUMAN   ANATOMY. 


Palmaris  longus^:  origin^  inner  epicondyle  by  the  common 
tendon,  fascia,  and  intermuscular  septa;  insertion^  tendinous 
into  the  anterior  annuhir  ligament  and  palmar  fascia,  espe- 
cially that  over  the  thenar  eminence ;  action^  tightens  the 
palmar  fascia,  flexes  the  wrist ;  nerve,  median. 

Flexor  carpi  ulnaris  "^ :  origin,  double,  by  the  common  tendon 
from  the  inner  epicondyle  and  from  the 
inner  margin  of  the  olecranon  by  an  apo- 
neurosis, and  from  the  upper  two-thirds 
of  the  posterior  border  of  the  ulna  and 
intermuscular  septum  ;  insertion,  tendi- 
nous into  the  pisiform  bone,  annular  liga- 
ment, unciform,  and  base  of  the  fifth  meta- 
carpal by  means  of  ligaments ;  action, 
flexes  the  hand  on  the  forearm  and  ad- 
ducts  ;  then  flexes  the  forearm  on  the 
arm  ;  nerve,  ulnar. 

Flexor  sublimis  digitorum  '  (perforatus)  : 
origin,  by  three  heads,  one  from  the  inner 
epicondyle  by  the  common  tendon  and 
from  the  internal  lateral  ligament  and 
the  intermuscular  septa,  a  second  from 
the  inner  side  of  the  coronoid  process 
of  the  ulna,  the  third  from  the  oblique 
line  of  the  radius ;  insertion,  by  four 
tendons,  each  of  which  splits  for  the  pas- 
sage of  the  deep  flexor  tendon,  each  half 
becoming  attached  to  the  middle  of  the 
lateral  margins  of  the  second  phalanges ; 
action,  flexes  the  fingers,  then  the  hand 
on  the  forearm,  then  the  forearm  on  the 
arm  ;  nerve,  median. 


Fig.  93.— Muscles  of  the 
anterior  region  of  the 
right  forearm  and  hand 
(Leidy). 


Deep  layer. 

Flexor  profundus  digitorum   (perforans)  : 

origin,  upper  three-fourths  of  the  anterior 
and  internal  surfaces  of  the  ulna,  inner  side  of  the  coronoid  proc- 
ess, by  an  aponeurosis  from  the  upper  three-fourths  of  the  pos- 
terior border  of  the  ulna  and  ulnar  half  of  the  interosseous 
membrane ;  insertion,  into  bases  of  the  last  phalanges  by  four 
tendons,  which  pass  between  the  two  slips  of  the  flexor  sub- 


MUSCLES  OF  THE  FOREARM. 


165 


limis  tendons  ;  action^  flexes  the  fingers,  then  the  wrist  on  the 
forearm  ;  nerves,  ulnar  and  anterior  interosseous  of  the  median. 

Flexor  longus  pollicis  :  origin,  anterior  surface  of  the  radius 
from  the  oblique  line  to  the  pronator  quadratus,  adjacent  inter- 
osseous membrane,  usually  a  second  head 
from  the  base  of  the  coronoid  process  or 
in  common  with  the  flexor  sublimis  from 
the  inner  epicondyle  ;  insertion,  base  of 
the  lapt  phalanx  of  the  thumb ;  action, 
flexes  the  last  thumb-phalanx  and  wrist ; 
nerve,  anterior  interosseous  of  the  median. 

Pronator  quadratus  :  origin,  oblique  line 
on  the  lower  fourth  of  the  anterior  sur- 
face of  the  ulna,  the  bone  below  this  line, 
the  anterior  border  of  the  ulna  and  apo- 
neurosis over  the  muscle  ;  insertion,  lower 
fourth  of  the  anterior  surface  and  exter- 
nal border  of  the  radius  ;  action,  pronates 
the  radius  upon  the  ulna ;  nerve^  anterior 
interosseous  of  the  median. 

Radial  region: 

Nearly  all  the  extensors  and  supinators 
arise  from  the  external  epicondyle  and 
supracondylar  ridge  of  the  humerus. 


Supinator  longus  (brachio-radialis)' 


:  om- 


gin,  upper  two-thirds  of  the  external  su- 
pracondylar ridge  and  anterior  surface  of 
the  external  intermuscular  septum  ;  in- 
sertion, base  of  the  styloid  process  of  the 
radius ;  action,  supinates  forearm  after  it 
has  been  pronated,  pronates  after  supina- 
tion, flexes  the  forearm  on  the  arm  ;  nerve, 
musculo-spiral. 

Extensor  carpi  radialis  longior^  (^^ig- 
94)  :  origin,  lower  third  of  the  external  supracondylar  ridge 
and  anterior  surface  of  the  external  intermuscular  septum  ; 
ivsrrfion,  radial  side  of  the  })ase  of  the  metacarpal  bone  of  the 
index  fini^er  ;  action,  extends  and  abducts  the  wrist  and  flexes 
the  elbow  ;  nerve,  musculo-spiral. 

Extensor  carpi  radialis  brevior " :  origin,  external  condyle  by 


Fig.  91.— Muscles  ofthe 
j)()steri<)r  region  of  the 
right  forearm  and  hand 
(Leidy). 


166  ESSENTIALS  OF  HUMAN  ANATOMY. 

the  common  tendon,  external  lateral  ligament,  the  covering 
aponeurosis,  and  the  intermuscular  septa  ;  insertion,  contiguous 
sides  of  the  bases  of  the  second  and  third  metacarpal  bones ; 
action,  extends  the  wrist  and  weakly  extends  the  elbow  ;  nerve, 
posterior  interosseous. 

Posterior  radio-ulnar  region  ;  superficial  layer : 

Extensor  communis  digitorum*:  origin,  external  epicondyle  by 
the  common  tendon,  deep  fascia,  and  intermuscular  septa  ;  insei^- 
tion,  tendon  expands  over  the  first  phalanx,  divides  into  three 
parts:  the  middle  part  goes  to  the  second  phalanx,  the  two 
lateral  unite  on  the  last ;  action,  extends  the  fingers,  wrist,  and 
elbow-joint ;  nerve,  posterior  interosseous. 

Extensor  minimi  digiti^:  origin,  intermuscular  septa,  rarely 
reaches  the  common  tendon  ;  insertion,  by  two  tendons  which 
join  the  common  extensor  into  the  phalanges  of  the  little 
finger ;  action,  extends  the  little  finger ;  nerve,  posterior  inter- 
osseous. 

Extensor  carpi  ulnaris  ^° :  origin,  by  the  common  tendon  from 
the  external  epicondyle,  from  the  deep  fascia,  intermuscular 
septa,  with  a  second  head  from  the  posterior  border  of  the 
ulna ;  insertion,  ulnar  side  of  the  base  of  the  fifth  metacarpal ; 
action,  extends  and  adducts  the  wrist ;  extends  the  elbow ; 
nerve,  posterior  interosseous. 

Anconeus  :  origin,  back  of  the  outer  condyle  of  the  humerus  ; 
insertion,  side  of  the  olecranon  and  upper  fourth  of  the  poste- 
rior surface  of  the  shaft  of  the  ulna  above  the  oblique  line ; 
action,  extends  the  forearm  ;  nerve,  musculo-spiral. 

Deep  layer: 

Supinator  brevis^':  origin,  external  condyle  of  the  humerus, 
external  lateral  ligament  and  orbicular  ligament  of  the  radius, 
supinator  ridge  of  the  ulna,  triangular  depression  in  front  of  it 
and  aponeurosis  covering  the  muscle ;  insertion,  encircling  the 
neck  of  the  radius  posteriorly,  it  is  attached  to  the  upper  third 
of  the  shaft,  the  bicipital  tuberosity,  and  the  oblique  line; 
action,  supinates  and  extends  the  forearm  ;  nerve,  posterior 
interosseous,  which  pierces  it. 

Extensor  ossis  metacarpi  poUicis^' :  origin,  posterior  surface  of 
the  shaft  of  the  ulna  below  the  anconeus,  interosseous  membrane, 
and  middle  third  of  the  posterior  surface  of  the  shaft  of  the 


FASCIA  OF  THE   HAND.  167 

radius  ;  insertion,  radial  side  of  the  base  of  the  first  metacarpal, 
often  a  second  slip  to  the  trapezium  or  to  the  abductor  poUicis  ; 
action,  extends  the  first  metacarpal;  )ierve,  posterior  interosseous. 

Extensor  brevis  poUicis^^ :  origin,  posterior  surface  of  the  shaft 
of  the  radius  and  interosseous  membrane  ;  insertion,  base  of  the 
first  phalanx  of  the  thumb  ;  action,  extends  the  phalanx  on  the 
metacarpal,  abducts  the  wrist ;  nerve,  posterior  interosseous. 

Extensor  longus  poUicis^* :  origin,  posterior  surface  of  the  shaft 
of  the  ulna  and  interosseous  membrane  below  the  extensor  ossis 
metacarpi ;  insertion,  last  phalanx  of  the  thumb  ;  action,  extends 
the  thumb,  abducts  the  wrist ;  nerve,  posterior  interosseous. 

Extensor  indicis :  origin,  posterior  surface  of  the  shaft  of  the 
ulna  below  the  extensor  longus  ;  insertion,  with  the  tendon  of  the 
common  extensor  into  the  phalanges  of  the  index  finger  on  the 
ulnar  side;  action,  extends  the  index  finger  and  wrist;  nerve^ 
posterior  interosseous. 

Fasciae  of  the  Hand. 

The  anterior  annular  ligament  is  stretched  between  the  emi- 
nentia  carpi,  which  are  the  pisiform  bone  and  the  unciform 
process  on  one  side,  and  the  tuberosity  of  the  scaphoid  and  the 
ridge  of  the  trapezium  on  the  other ;  it  is  continuous  with  the 
deep  fascia  of  the  forearm  and  the  palmaris  longus  tendon,  and 
is  pierced  by  that  of  the  flexor  carpi  radialis  ;  beneath  it  pass 
the  median  nerve  and,  in  one  synovial  sheath,  the  tendons  of 
the  flexor  sublimis  and  profundus  digitorum,  and  in  a  single 
sheath  the  tendon  of  the  flexor  longus  pollicis. 

The  posterior  annular  ligament,  continuous  with  the  forearm 
fascia,  is  attached  internally  on  the  dorsum  to  the  ulna,  cunei- 
form, and  pisiform  bones  and  palmar  fascia  externally,  to  the 
ridges  on  the  back  of  and  margin  of  the  radius.  Six  separate 
synovial  compartments  exist  for  the  extensor  tendons  ;  from 
without  inward  they  are:  (1)  outer  side  of  the  styloid  process, 
for  the  extensor  ossis  metacarpi  and  extensor  brevis  pollicis  ; 
(2)  behind  same  process,  for  the  extensor  carpi  radialis  longior 
and  brevior  ;  (3)  next  for  the  extensor  longus  pollicis  ;  (4)  more 
internally  still,  for  the  extensor  communis  digitorum  and  ex- 
tensor indicis  ;  (J))  opposite  the  interval  between  the  radius  and 
ulna,  for  the  extcn.sor  minimi  digiti ;  and  (6)  back  of  the  ulna, 
for  the  extensor  carjM  ulnaris. 

TIh'  palmar  fascia^  ('''c?-  •^'^)i  <'onsisting  of  a  central  and  two 


168  ESSENTIALS  OF   HUMAN   ANATOMY. 

lateral  portions,  invests  the  muscles  of  the  hand,  forming  their 
common  sheath  ;  the  central  segment  is  triangular,  attached  to 
the  })alniaris  longus  and  anterior  annular  ligament  above,  below 
dividing  into  four  slips  opposite  the  metacarpal  heads,  each  slip 
dividing  again  to  enclose  the  flexor  tendons  and  be  inserted  on 
the  sides  of  the  first  phalanges ;  strong  transverse  fibers  con- 
nect the  separate  processes,  and  vertical  septa,  continuous  on 
each  side  with  the  interosseous  aponeurosis,  separate  the  middle 
from  the  lateral  palmar  groups  of  muscles ;  beneath  is  the  su- 
perficial palmar  arch,  median  and  ulnar  nerves  ;  the  lateral  por- 
tions of  this  fascia  thinly  invest  the  muscles  of  the  thenar  and 
hypothenar  eminences. 

Muscles  of  the  Hand. 

Abductor  poUicis'^  (l^ig-  93):  origin,  ridge  of  the  trapezium 
and  annular  ligament ;  iiii^ertion^  tendinous  into  the  radial  side 
of  the  base  of  the  first  thumb-phalanx ;  action^  draws  the  thumb 
from  the  median  line — i.  e.  abducts  it ;  nerve,  median. 

Opponens  pollicis :  origin,  palmar  surface  of  the  trapezium 
and  annular  ligament ;  insertion,  whole  length  of  the  radial 
side  of  the  thumb-metacarpal ;  action,  flexes  the  metacarpal ; 
nerve,  median. 

Flexor  brevis  pollicis'''  (Fig.  93):  origin,  by  two  heads,  the 
external  from  the  trapezium  and  outer  two-thirds  of  the  an- 
nular ligament ;  the  internal  rises  from  the  inner  side  of  the 
base  of  the  first  metacarpal  between  the  abductor  indicis  and 
adductor  obliquus  pollicis  ;  insertion,  sides  of  the  base  of  the 
first  thumb-phalanx  by  two  tendons,  each  containing  a  sesa- 
moid bone  ;  action,  as  name  implies ;  nerves,  median  and  ulnar. 

Adductor  obliquus  pollicis  rises  from  the  os  magnum,  bases  of 
the  second  and  third  metacarpals,  and  tendon-sheath  of  the 
flexor  carpi  radialis  ;  insertion,  ulnar  side  of  the  base  of  the  first 
thumb-phalanx  and  internal  sesamoid  bone,  and  sends  a  fas- 
ciculus under  the  flexor  longus  tendon  to  the  outer  side  of  the 
base  of  the  first  phalanx  ;  action,  draws  the  thumb  inward  to- 
ward the  median  line  ;  nerve,  ulnar. 

Adductor  transversus  pollicis:  origin,  lower  two-thirds  of  the 
third  metacarpal  ;  insertion,  ulnar  side  of  the  base  of  the  first 
phalanx  of  the  thumb ;  action,  flexes  the  phalanx,  adducts  the 
thumb;   nerve,  \\\\\i\r. 

The  preceding  muscles  form  the  thenar  eminence. 


MtJSCLES  O^  THE   LOWER  EXTREMITY.  169 

Palmaris  brevis  "^ :  origin,  tendinous  from  the  annular  liga- 
ment and  palmar  fascia  ;  insertion^  skin  on  the  inner  border  of 
the  palm  ;  action,  wrinkles  the  skin  on  the  inner  palmar  side  ; 
nerve,  ulnar. 

Abductor  minimi  digiti:  origin,  pisiform  bone  and  expansion 
of  the  tendon  of  the  flexor  carpi  ulnaris  ;  insertion,  ulnar  side 
of  the  base  of  the  first  phalanx  of  the  little  finger;  action, 
draws  the  little  finger  from  the  median  line  and  flexes  the 
metacarpo-phalangeal  joint ;   nerve,  ulnar. 

Flexor  brevis  minimi  digiti:  origin,  tip  of  the  unciform  process 
and  from  the  annular  ligament;  insertion,  base  of  the  first  pha- 
lanx of  the  little  finger  with  the  abductor;  action,  flexes  the 
first  phalanx  ;  nerve,  ulnar. 

Opponens  minimi  digiti :  origin,  beneath  the  preceding,  from  the 
unciform  process  and  annular  ligament ;  insertion,  whole  length 
of  the  fifth  metacarpal ;  action,  flexes  the  fifth  metacarpal,  and 
draws  forward  to  deepen  the  hollow  of  the  palm  ;  nerve,  ulnar. 

The  four  preceding  muscles  form  the  liypotlienar  eminence. 

Lumbricales:  origin,  tendons  of  the  deep  flexor;  insertion,  on 
radial  side  into  the  expansion  of  the  extensor  communis  tendon 
over  the  dorsum  of  each  finger;  they  are  four  in  number;  action, 
flex  the  first  and  extend  the  last  two  phalanges  ;  nerves,  two 
outer  by  the  median,  two  inner  by  the  ulnar. 

Dorsal  interossei  (four  in  number)  :  origin,  by  two  heads  from 
adjacent  sides  of  the  metacarpal  bones ;  insertion,  into  bases  of 
the  first  phalanges  and  aponeurosis  of  the  common  extensor ; 
action,  flex  the  first  and  extend  the  last  two  phalanges,  ab- 
duct the  fingers  from  a  line  passing  through  the  center  of  the 
middle  finger  ;  nerve,  ulnar. 

Palmar  interossei  (three  in  number)  :  origin,  by  single  heads, 
from  the  palmar  surface  of  the  second,  fourth,  and  fifth  meta- 
carpals;  insertion,  into  three  fingers  as  above;  action,  flex  the 
first,  extend  the  last  two  phalanges,  and  adduct  the  fingers 
toward  the  middle  finger;  nerve,  ulnar. 

Muscles  of  the  Lower  Extremity. 

Psoas  magnus"  (Fig.  i>5)  :  origin,  margins  of  the  bodies,  in- 
tervertebral siibstances  and  bases  of  the  transver.sc  processes 
of  the  last  thoracic  and  all  the  lumbar  vertebrae  ;  insertion,  ten- 
dinous, with  the  iliacus,  into  the  lesser  trochanter  ;  action,  flexes 


170  ESSENTIALS  OF  HUMAN   ANATOMY. 

the  thigh  on  the  pelvis,  or  vice  versa ;  also  rotates  the  femur 
outward  ;  nerves,  anterior  branches  of  the  second  and  third 
lumbar. 

Psoas  parvus  (often  absent)  :  origin,  margins  of  the  bodies 
and  intervertebral  substance  between  the  last  thoracic  and  the 
first  lumbar  vertebrae ;  insertion,  tendinous  into  the  ilio-pecti- 
neal  eminence  and  iliac  fascia  ;  action,  tensor  of  the  iliac  fascia ; 
nerve,  anterior  branch  of  the  first  lumbar. 

Iliacus^'^:  origin,  upper  half  of  the  iliac  fossa  and  inner  mar- 
gin of  the  iliac  crest,  ilio-lumbar  ligament  and  base  of  the  sa- 
crum, anterior  superior  and  inferior  iliac  spines,  the  notch  be- 
tween them  ;  insertion,  with  the  tendon  of  the  psoas  magnus 
into  the  lesser  trochanter;  actio)i,  same  as  the  psoas  magnus; 
nerve,  anterior  crural. 

The  fascia  lata,  or  deep  fascia,  is  attached  above  to  Poupart's 
ligament  and  the  iliac  crest,  behind  to  the  margins  of  the  sacrum 
and  coccyx,  internally  to  the  pubic  arch  and  linea  ilio-pectinea, 
and  below  to  the  condyles  of  the  femur,  tuberosities  of  the 
tibia,  and  head  of  the  fibula  ;  three  intermuscular  septa  pass 
from  its  inner  surface  to  the  whole  length  of  the  linea  aspera ; 
numerous  smaller  septa  provide  separate  sheaths  for  each  mus- 
cle ;  just  below  Poupart's  ligament,  at  the  upper  inner  aspect 
of  the  thigh,  is  the  large  oval  sajyhenous  opening,  formed  by  the 
margins  of  the  pubic  and  iliac  portions  of  the  fascia  lata  ;  Pou- 
part's ligament  is  an  artificial  production,  being  in  reality  the 
thickened  lower  portion  of  the  external  oblique  aponeurosis 
where  the  fascia  lata  becomes  continuous  with  it. 

Tensor  fasciae  femoris*:  origin,  anterior  part  of  the  outer  lip 
of  the  iliac  crest  and  anterior  superior  iliac  spine  ;  insertion, 
fascia  lata  one-fourth  down  the  thigh,  whence  the  fascia  is  con- 
tinued down  to  the  tibial  head  as  the  ilio-tihial  hand ;  action, 
tensor  of  the  fascia  lata  and  internal  rotator  of  the  thigh  ;  nerve, 
superior  gluteal. 

Sartorius^:  origin,  anterior  superior  iliac  spine  and  upper 
half  of  the  notch  below  it ;  insertion,  aponeurotic  into  the 
upper  inner  surface  of  the  shaft  of  the  tibia  ;  action,  flexes  the 
leg  upon  the  thigh,  the  thigh  upon  the  pelvis,  and  rotates  out, 
at  the  same  time  drawing  the  limb  inward,  thus  crossing  one 
leg  over  the  other ;  nerve,  anterior  crural. 

Rectus  femoris^:  origin,  by  two  tendons,  the  straight  from  the 
anterior  inferior  iliac  spine,  the  rejiected  from  the  groove  above 


MUSCLES  OF  THE  THIGH. 


171 


the  acetabulum  ;  insertion^  patella  in  common  with  the  three 
next  muscles  ;  action.,  extends  the  leg  and  flexes  the  hip-joint ; 
nerve.,  anterior  crural. 

Vastus  externus  '  :   origin.,  tubercle  of  the  femur,  great  tro- 
chanter, rough  line  leading  thence  to  the  linea  aspera,  upper 


Fig.  9".  — >ruscles  of  the  iliac  and  Fir,.  %— Muscles  of  tlie  gluteal 

anterior  femoral  regions.     ,    . ,    .   and  posterior  femoral  regions. 

half  of  the  outer  lip  of  the  linea  aspera,  and  external  inter- 
muscular septum  ;  insertion,  aponeurotic  into  the  outer  bor- 
der of  the  patella ;  action,  extends  the  leg ;  nerve,  anterior 
crural. 


172  ESSENTIALS  OF  HUMAN   ANATOMY. 

Vastus  Internus  and  crureus^:  origin^  line  leading  from  the 
inner  side  of  the  neck  of  the  femur  to  the  linea  aspera  and  its 
whole  inner  lip,  lower  half  of  the  outer  lip,  internal  inter- 
muscular septum,  internal,  anterior,  and  external  surfaces  of 
the  shaft  of  the  femur  between  the  anterior  intertrochanteric 
line  and  the  lower  fourth  of  the  bone ;  insertion,  aponeurotic, 
into  the  inner  side  of  the  patella,  blending  with  other  portions  of 
the  quadriceps  tendon  ;  action,  extends  the  leg  ;  nerve,  anterior 
crural.  The  preceding  four  muscles  are  called  the  quadriceps 
femoris^,  \  ®,  whose  tendon  contains  the  patella^,  and  is  inserted 
into  the  tubercle  of  the  tibia  by  the  ligamentum  patellae. 

Subcrureus  :  origin,  often  by  two  heads  from  the  lower  part 
of  the  shaft  of  the  femur  ;  insertion,  upper  part  of  the  synovial 
pouch  of  the  knee-joint ;  action,  draws  up  the  synovial  sac ; 
nerve,  anterior  crural. 

Gracilis  ^^i  origin,  aponeurotic  from  the  inner  margin  of  the 
body  and  descending  ramus  of  the  os  pubis  ;  insertion,  upper 
inner  surface  of  the  shaft  of  the  tibia  above  and  behind  the 
sartorius ;  action,  flexes  the  leg,  rotates  it  in,  and  adducts  the 
thigh  ;   nerve,  obturator. 

Pectineus  ^"^ :  origin,  linea  ilio-pectinea,  the  bone  in  front  of  it, 
and  from  fascia  covering  it ;  insert io)i,  rough  \me  passing  from 
the  lesser  trochanter  to  the  linea  aspera  ;  action,  flexes,  adducts, 
and  rotates  the  thigh  outward ;  nerves,  anterior  crural,  obtu- 
rator, and  accessory  obturator  in  order  of  frequency. 

Adductor  longus '^ :  origin,  body  of  the  os  pubis  just  below 
the  angle ;  insertion,  middle  third  of  the  linea  aspera ;  action, 
adducts  and  flexes  thethigh  and  rotates  out;   nerve,  obturator. 

Adductor  brevis :  origin,  the  body  and  outer  surface  of  the 
descending  ramus  of  the  os  pubis;  insertion,  upper  part  of  the 
linea  aspera ;  action,  adducts  and  flexes  the  thigh  ;  nerve,  ob- 
turator. 

Adductor  magnus^*:  origin,  descending  ramus  of  the  os  pubis, 
ascending  ramus,  outer  margin  and  under  surface  of  the  tuber- 
osity of  the  ischium  ;  insertion,  rough  line  running  from  the 
great  trochanter  to  the  linea  aspera,  whole  length  of  the  linea 
aspera,  and  by  a  tendon  into  the  tubercle  above  the  inner  con- 
dyle of  the  femur  ;  between  two  portions  of  the  muscle  is  an  in- 
terval for  the  passage  of  the  femoral  vessels  from  Hunter's  canal 
into  the  popliteal  space  ;  action,  adducts  and  rotates  the  thigh 
outward,  the  long  fibers  to  the  tubercle  may  rotate  in  ;  nerves, 


MUSCLES  OF  THE  THIGH. 


173 


obturator  and  great  sciatic  ;  the  portion  of  tlie  muscle  attached 
to  the  femur  presents  four  apertures  for  the  perforating  arteries. 

Gluteus  maximus  '^  (Fig.  96)  :  origin^  superior  gluteal  line  of 
the  ilium  and  portion  of  the  bone  and  crest  just  behind  it, 
posterior  surface  of  the  last  two  pieces  of  the  sacrum,  side  of  the 
coccyx,  aponeurosis  of  the  erector  spinse  muscle,  and  the  great 
sacro-sciatic  ligament ;  insertion,  the  fascia  lata  and  rough  line 
runnino;  from  the  great  trochanter  to  the  linea  aspera  between 
the  vastus  externus  and  the  adductor  magnus ;  action,  main- 
tains the  trunk  erect  upon  the  thigh,  extends,  abducts,  and 
rotates  the  thigh  outward,  is  a  tensor  of  the  fascia  lata ;  nerve, 
inferior  gluteal. 

Gluteus  medius^  (Fig.  96)  :  origin,  outer  surface  of  the  ilium  be- 
tween the  superior  and  the  middle  gluteal  lines,  outer  lip  of  the 
crest  between  the  lines,  and  the 
gluteal  aponeurosis ;  insertion, 
tendinous  into  the  oblique  line 
on  the  great  trochanter ;  action, 
supports  the  trunk  ;  the  poste- 
rior fibers  rotate  the  thigh  out- 
ward and  extend  ;  the  anterior 
fibers  flex  and  rotate  the  thigh 
inward ;  the  middle  fibers  ab- 
duct ;  nerve,  superior  gluteal. 

Gluteus  minimus  ^  (Fig.  97)  : 
origin,  outer  surface  of  the 
ilium  between  the  middle  and 
the  inferior  gluteal  lines  and 
margin  of  the  sciatic  notch  ; 
insertion,  anterior  border  of  the 
great  trochanter  ;  action,  flexes, 
abducts,  and  rotates  the  thigh 
inward,  aids  in  maintaining  the 
trunk  erect ;  nerve,  superior 
gluteal. 

Pyriformis  ■* :  origin,  by  three 
fleshy  digitations  from  the  sa- 
crum between  the  first,  second,  third,  and  fourth  anterior  sacral 
foramina,  from  grooves  leading  from  them,  from  the  ilium  below 
the  posterior  inferior  spine,  and  great  sacro-sciatic  ligament; 
insertion,  passing  out  of  the  pelvis  by  the  great  sacro-sciatic 


Fig.  97. — Muscles  of  the  hip, 
posterior  view  (Leidy). 


174  ESSENTIALS  OF  HUMAN  ANATOMY. 

foramen,  is  attached  to  the  upper  border  of  the  great  tro- 
chanter; action^  an  external  rotator  of  the  thigh  after  ex- 
tension, and  abductor  after  flexion  ;  also  draws  the  pelvis  for- 
ward when  tixed  below  ;  nerves,  branches  of  the  sacral  plexus. 

Obturator  internus '^  :  o/-/^//<,  internal  surface  and  tendinous 
arch  of  the  obturator  membrane,  margins  of  the  obturator  fora- 
men, broad  surface  of  the  bone  behind  foramen ;  insertion, 
inner  surface  of  the  great  trochanter  after  leaving  the  pelvis  by 
the  lesser  sacro-sciatic  foramen  ;  four  or  five  tendinous  bands 
pass  in  the  substance  of  the  muscle  from  its  origin  to  its  in- 
sertion ;  action,  similar  to  the  pyriformis ;  nerve,  branch  of  the 
sacral  plexus. 

Gemellus  superior  ^^ :  origin,  spine  of  the  ischium  ;  insertion, 
with  the  tendon  of  the  obturator  internus  into  the  inner  surface 
of  the  great  trochanter ;  action^  rotates  the  thigh  outward ; 
nerve,  from  the  branch  to  the  obturator  internus. 

Gemellus  inferior'"^:  origin,  tuberosity  of  the  ischium;  in- 
sertion, great  trochanter  with  the  obturator  internus ;  action, 
an  external  rotator  of  the  thigh  ;  nerve,  twig  from  the  branch 
to  the  ([uadratits  femoris. 

Obturator  externus :  origin,  inner  anterior  margin  of  the  ob- 
turator foramen  and  inner  two-thirds  of  the  outer  surface  of 
the  obturator  membrane  ;  insertion,  digital  fossa  of  the  femur  ; 
action,  an  external  rotator  of  the  thigh,  may  flex  and  adduct; 
nerve,  deep  branch  of  the  obturator. 

Quadratus  femoris^'':  origin,  outer  border  of  the  tuber  ischii ; 
insertion,  a  tubercle  at  the  center  of  the  posterior  intertro- 
chanteric line  ;  action,  external  rotator  of  the  thigh  and  an 
adductor :   nerve,  branch  of  the  sacral  plexus. 

Biceps  ^"^  *,^  (^ig-  ^6);  (Fig.  97)  :  origin,  by  two  heads,  the 
long  ^^  from  the  lower  inner  facet  on  the  tuber  ischii  by  the  tendon 
common  to  it  and  the  semitendinosus  and  from  the  great  sacro- 
sciatic  ligament,  the  sliort  head^  (Fig.  96),  from  the  linea  aspera 
between  the  adductor  magnus  and  the  vastus  externus,  and 
from  the  intermuscular  septum  ;  insertion,  outer  side  of  the 
head  of  the  fibula,  the  tendon  splitting  to  embrace  the  long 
external  lateral  ligament  of  the  knee,  one  band  extending  to  the 
outer  tuberosit}^  of  the  tibia ;  this  muscle  forms  the  outer 
hamstring  ;  action,  extends  the  hip,  flexes  the  leg,  after  which 
it  slightly  rotates  it  outward  ;  nerve,  great  sciatic. 

Semitendinosus^  (Fig.   96),^^  (Fig.  97):  origin,  by  the  com- 


MUSCLES  OF   THE   LEG.  1V5 

mon  tendon  with  the  biceps  to  the  length  of  three  inches  from 
the  tuberosity  of  the  ischium  and  adjacent  aponeurosis ;  iuHfr- 
tion^  upper  inner  surface  of  the  shaft  of  the  tibia,  behind  the 
sartorius  and  below  the  gracilis  ;  action^  extends  the  hip,  flexes 
the  leg  on  the  thigh,  rotates  it  in;  nerve,  great  sciatic. 

Semimembranosus^  (Fig-  96):  origin,  tendinous  from  the 
upper  outer  facet  on  the  tuberosity  of  the  ischium  ;  insertion, 
groove  on  the  inner  tuberosity  of  the  tibia,  connected  with  the 
popliteal  oblique  ligament  and  with  the  fascia  covering  the  pop- 
liteus  muscle,  a  few  fibers  forming  the  short  internal  lateral 
ligament  of  the  knee-joint ;  action,  extends  the  hip,  flexes  the 
leg  on  the  thigh,  rotates  it  in  ;  nerve,  great  sciatic  ;  the  tendons 
of  the  semimembranosus  and  semitendinosus  form  the  inner 
hamstrings. 

Muscles  of  the  Leg. 

Tibialis  anticus^  (Fig.  08)  :  origin,  outer  tuberosity  and  upper 
two-thirds  of  the  external  surface  of  the  shaft  of  the  tibia,  ad- 
jacent interosseous  membrane,  deep  surface  of  the  fascia,  and 
intermuscular  septum  ;  insertion,  inner  and  under  surface  of 
the  front  part  of  the  internal  cuneiform  bone,  base  of  the  first 
metatarsal ;  action,  flexes  the  ankle-joint,  rotates  the  foot  in- 
ward,  adducts  the  forefoot ;  nerve,  anterior  tibial. 

Extensor  longus  ballucis^:  origin,  middle  two-fourths  of  the 
anterior  surface  of  the  fibula,  and  to  the  same  extent  from  the 
interosseous  membrane  ;  insertion,  base  of  the  last  phalanx  of  the 
great  toe,  usually  with  a  slip  to  the  base  of  the  first  phalanx  ; 
action,  extends  the  great  toe,  otherwise  same  as  the  tibialis  an- 
ticus  ;   nf^rre.  anterior  tibial. 

Extensor  longus  digitorum*:  origin,  outer  tuberosity  of  the 
tibia,  upper  two-thirds  of  the  anterior  surface  of  the  fibula, 
interosseous  membrane,  deep  surface  of  the  fascia,  and  inter- 
muscular septa;  insertion,  divides  into  four  tendons,  which  are 
attached  to  the  three  phalanges  of  the  four  lesser  toes ;  action^ 
extends  the  toes,  flexes  the  ankle,  everts  the  foot,  abducts  the 
forefoot ;  nerve,  anterior  tibial. 

Peroneus  tertius'':  origin,  lower  third  of  the  anterior  surface 
of  the  fibula,  interosseous  membrane,  and  intermuscular  sep- 
tum ;  insertion,  upper  part  of  the  bases  of  the  fourth  and  fifth 
metatarsals ;  nerve  and  action  on  the  foot  same  as  those  of 
the  long  extensor. 


176 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Gastrocnemius  •'' :  origin^  by  two  heads  from  the  upper  back 
part  of  the  condyles  of  the  femur  and  supracondyLar  ridges ; 
insertion^  with  the  tendons  of  the  soleus  and  pUmtaris  to  form 
the  tendo  AchilHs,  which  is  inserted  into  the  middle  part  of  the 


Ivi 


Fig.  98.— Anterior  muscles  of  the  Fig.  99.— Posterior  muscles  of  the 

right  leg.  (Leidy.)  left  leg,  deep  layer. 

tuberosity  of  the  os  calcis  ;  action.,  extends  the  foot  and  slightly 
rotates  it  in  ;  nerve.,  internal  popliteal. 

Soleus^/:  origin,  tendinous,  from  the  back  of  the  head  and 
upper  third  of  the  posterior  surface  of  the  fibula,  from  the  ob- 
lique line  of  the  tibia,  and  from  the  middle  third  of  its  inner 
border ;   imertion,  tuberosity  of  the  os  calcic  by  the  tendo 


MUSCLES  OF  THE   LEG.  177 

Achillis ;  action^  as  above  ;  nerves,  internal  popliteal  and  poste- 
rior tibial. 

Plantaris:  origin,  lower  part  of  the  outer  bifurcation  of  the 
linea  aspera  and  posterior  ligament  of  the  knee-joint;  insertion, 
posterior  surface  of  the  os  calcis  with  the  tendo  Achillis,  into 
the  tendo  Achillis,  or  into  the  plantar  fascia  ;  action,  accessory 
to  the  gastrocnemius  ;  nerve,  internal  popliteal. 

Popliteus*^  (Fig.  99)  :  origin,  within  the  knee-joint  from  the 
depression  on  the  outer  side  of  the  external  condyle  of  the 
femur,  and  from  the  arcuate  ligament  or  posterior  part  of  the 
capsule;  insertion,  trianguhir  surface  above  the  oblique  line  of 
the  tibia  posteriorly,  and  tendinous  expansion  covering  the 
muscle  ;  action,  flexes  the  leg  upon  the  thigh,  then  rotates  the 
tibia  inward,  and  draws  the  capsule  backward  ;  nerve,  internal 
popliteal. 

Flexor  longus  hallucis^  (Fig.  99)  :  origin,  lower  two-thirds  of 
the  posterior  surface  of  the  fibula,  except  its  lowest  inch, 
lower  part  of  the  interosseous  membrane,  intermuscular  septum, 
deep  fascia,  and  fascia  covering  the  tibialis  posticus;  insertion, 
base  of  the  last  phalanx  of  the  great  toe  ;  in  the  foot  always 
giving  a  tendon  to  the  flexor  longus  digitorum  ;  action,  flexes 
the  great  toe,  then  extends  the  foot ;  nerve,  posterior  tibial. 

Flexor  longus  digitorum"  (Fig.  99):  origin,  posterior  surface 
of  the  tibia  below  the  oblique  line  internal  to  the  tibialis  pos- 
ticus, except  the  lower  three  inches,  deep  fascia,  also  the  inter- 
muscular septum  ;  its  tendon  passes  behind  the  malleolus  in  the 
groove  with  the  tibialis  posticus,  but  in  a  separate  synovial 
sheath  ;  insertion,  bases  of  the  phalanges  of  the  lesser  toes  by 
four  tendons,  each  passing  through  a  fissure  in  the  tendon  of 
the  flexor  brevis  ;  action,  flexes  the  phalanges,  and  then  extends 
the  foot ;  nerve,  posterior  tibial.  With  this  muscle  are  connected 
the  lumbriealcs  and  the  accessorius. 

Tibialis  posticus''  (Fig.  99):  origin, hy  two  pointed  processes, 
between  which  pass  the  anterior  tibial  vessels,  from  the  whole 
of  the  posterior  surface  of  the  interosseous  membrane  exce|>t  the 
lowest  part,  posterior  surface  of  the  tibia,  external  to  the  flexor 
longus,  between  tli(!  o})li(nie  line  above  and  the  middle  of  the  ex- 
ternal bonier  Ixilow,  and  from  the  whoh;  of  tlie  internal  surface 
of  tli(!  fibula;  insertion,  tuberosities  of  the  navicular  and  inter- 
n;il  (Mirieiform,  and  sends  oftsets  to  the  middle  and  external  cunei- 
form, cuboid,  sustentaculum  tali,  and  bases  of  the  second,  third, 
12 


178  ESSENTIALS  OF   HUMAN    ANATOMY. 

and  fourth  metatarsals  ;  action^  extends  the  foot,  adducts  and 
rotates  in  :   iim-c.  posterior  tibial. 

Peroneus  longus'  (Fig.  98):  origin,  outer  tuberosity  of  the 
tibia,  head  and  upper  two-thirds  of  the  outer  surface  of  the 
fibula,  deep  surface  of  the  fascia,  and  intermuscular  septa, 
then  it  grooves  the  outer  malleolus  with  the  peroneus  brevis", 
then  the  os  calcis  and  cuboid  ;  insertion,  outer  side  of  the  base 
of  the  first  metatarsal  and  internal  cuneiform  ;  action,  extends 
and  everts  the  foot;  neive,  musculo-cutaneous. 

Peroneus  brevis''  (Fig.  98):  origin,  lower  two-thirds  of  the 
outer  surface  of  the  shaft  of  the  fibula,  intermuscular  septa  ; 
insertion,  passes  with  the  preceding  muscle  behind  the  external 
malleolus  in  a  groove  lined  with  a  common  synovial  sheath,  to 
be  attached  to  the  dorsum  of  the  base  of  the  fifth  metatar.sal, 
and  sends  a  slip  to  the  long  extensor  of  the  little  toe ;  action 
and  nerve,  same  as  the  peroneus  longus. 

Fasciae  of  the  Foot. 

The  anterior  annular  ligament  consists  of  (1)  an  upper  verti- 
cal portion  binding  down  the  extensor  tendons,  attached  to  the 
lower  ends  of  the  tibia  and  fibula,  continuous  above  with  the 
deep  fascia,  and  containing  only  one  synovial  sheath  situated 
internally  for  the  tendon  of  the  tibialis  anticus  ;  the  exten- 
sor longus  digitorum.  peroneus  tertius.  and  extensor  longus 
hallucis  tendons,  the  anterior  tibial  vessels  and  nerve  pass  be- 
neath it  without  a  distinct  sheath  ;  and  (2)  a  horizontal  portion 
attached  externally  to  the  upper  surface  of  the  os  calcis,  and 
internally  are  two  diverging  arms,  one  to  the  inner  malleolus 
and  one  to  the  plantar  fascia,  containing  three  sheaths,  that  in- 
ternal for  the  tendon  of  the  tibialis  anticus,  the  next  for  the 
extensor  longus  hallucis.  and  that  most  external  for  the  ex- 
tensor longus  digitorum  and  peroneus  tertius. 

The  internal  annular  ligament  is  a  strong  band  extending  from 
the  inner  malleolus  to  the  inner  margin  of  the  os  calcis.  convert- 
ing  the  bony  grooves  on  its  surface  into  canals  for  the  flexor 
tendons  and  the  tibial  vessels  and  nerves  ;  it  is  continuous  with 
the  deep  fascia  of  the  leg,  plantar  fascia,  and  the  origin  of  the 
abductor  hallucis  muscle.  Its  three  fibro-osseous  canals  trans- 
mit, enumerated  obliquely  from  within  outward,  the  tendons  of 
the  tibialis  posticus,  flexor  longus  digitorum.  posterior  tibial 


MUSCLES  OF  THE   FOOT.  179 

vessels  and  nerve — through  a  broad  space  beneath  the  liga- 
ment— and  the  tendon  of  the  flexor  lono-us  hallucis. 

The  external  annular  ligament  stretches  between  the  extremity 
of  the  outer  malleolus  to  the  outer  surface  of  the  os  calcis, 
forming  a  common  sheath  for  the  peroneal  tendons. 

The  plantar  fascia,  the  densest  of  all  fibrous  membranes,  con- 
sists of  a  central  and  two  lateral  parts;  the  former,  thick  and 
narrow  behind,  arising  from  the  inner  tubercle  of  the  os  calcis, 
divides  into  a  process  for  every  toe.  each  again  splitting  oppo- 
site the  metatarso-phalangeal  joint  into  two  slips — over  which 
passes  the  flexor  tendon — to  be  attached  to  the  sides  of  the 
metatarsal  bone  and  transverse  metatarsal  ligament ;  two  chief 
and  several  subordinate  intermuscular  septa  are  given  off",  sepa- 
rating the  muscular  layers  ;  the  outer  and  inner  segments  are 
thin,  the  outer  has  one  strong  band  giving  origin  in  part  to  the 
abductor  minimi  digiti. 

Muscles  of  the  Foot. 

Dorsal  region. 

Extensor  brevis  digitorum:  origin,  outer  surface  of  the  os  cal- 
cis. external  calcaneo-astragaloid  ligament,  and  annular  liga- 
ment ;  insertion^  by  four  tendons,  the  first  into  the  first  phalanx 
of  the  great  toe,  and  is  named  the  extensor  hrevis  halhtcis ;  the 
other  three  into  the  outer  sides  of  the  long  extensor  tendons 
of  the  second,  third,  and  fourth  toes;  action,  accessory  to  the 
extensors  on  the  four  inner  toes ;  nerve,  anterior  tibial. 

Plantar  region.    First  layer. 

Abductor  hallucis^  (Fig.  100)  :  origin,  inner  tubercle  of  the  os 
calcis,  internal  annular  ligament,  navicular  bone,  plantar  fascia, 
and  intermuscular  septum;  insertion,  with  inner  tendon  of  the 
flexor  brevis  hallucis  into  the  inner  side  of  the  base  of  the  first 
phalanx  of  the  great  toe ;  action,  abducts  the  great  toe  ;  nerve, 
internal   plantar. 

Flexor  brevis  digitorum '^  :  origin,  tendinous  from  the  inner 
tubercle  of  the  os  calcis,  central  part  of  the  plantar  fascia 
and  the  intermuscular  septa  ;  insertion,  by  four  tendons  to  the 
four  lesser  toes,  perforated  opposite  the  middle  of  the  first 
ph;ihing(!s  by  the  tendons  r>f  the  long  flexor;  Iteyond  the  per- 
forations the  tendons  split  to  be  inserted  into  the  sides  of  the 


180 


e>sp:ntials  of  human  anatomy. 


second  phalanges  ;  action^  flexes  the  lesser  toes  ;  nerve^  internal 

plantar. 

Abductor  minimi  digiti  * :   origin,  outer  tubercle  of  the  os  cal- 

cis,  the   bone   in   front   of  both   tubercles,  plantar  fjiscia,  and 

intennuscular  septum  ;  insertion,  with 
the  short  flexor  of  the  little  toe  into  the 
outer  side  of  the  base  of  the  first  pha- 
lanx ;  action ,  abducts  the  little  toe  ;  nerve, 
external  plantar. 

Second  layer. 

Flexor  accessorius  :  origin,  by  two  heads, 
from  the  concave  surface  of  the  calcis 
and  inferior  calcaneo-navicular  ligament, 
from  the  os  calcis  in  front  of  the  outer 
tubercle,  and  from  the  long  plantar  liga- 
ment ;  insertion,  outer  margin  and  upper 
and  under  surfaces  of  the  tendon  of  the 
long  flexor  of  the  toes;  action,  modifies 
the  oblique  pull  of  the  long  flexor  ;  nerve, 
external  plantar. 

Lumbricales  ^ :  origin,  tendons  of  the 
long  flexor  ;  insertion,  expansion  of  the 
long  extensor  over  the  first  phalanges ; 
action,  flex  the  first  phalanx,  extend  the 
last  two  ;  nerves,  the  innermost  lumbri- 
calis  by  the  internal,  the  three  outer  by 
the  external  plantar  nerve. 

Third  layer. 

Flexor  brevis  hallucis  :  origin,  inner  border  of  the  cuboid  and 
contiguous  portion  of  the  external  cuneiform,  and  prolongation 
of  the  tibialis  posticus  tendon ;  insertion,  inner  and  outer  side 
of  the  base  of  the  first  phalanx  of  the  great  toe  by  two 
tendons,  each  containing  a  sesamoid  bone,  the  inner  tendon 
blending  with  that  of  the  abductor  hallucis,  the  outer  with  that 
of  the  adductor  obliquus  and  the  adductor  transversus  hallucis  : 
action,  flexes  the  great  toe  ;  nerve,  internal  plantar. 

Adductor  obliquus  hallucis:  origin,  tarsal  extremities  of  the 
second,  third,  and  fourth  metatarsal  bones  and  sheath  of  the 
tendon  of  the  peroncus  longus  ;   insertion,  with  outer  portion  of 


Fig.  100— :>ruRcles  of 
the  sole  of  the  foot,  first 
layer  (Leidy). 


THE  VASCULAR  SYSTEM.  181 

the  short  flexor  into  the  outer  side  of  the  base  of  the  first 
phahinx  of  the  great  toe  ;  action^  adducts  the  great  toe  ;  nerve, 
external  plantar. 

Adductor  transversus  hallucis :  ryrigin,  inferior  metatarso- 
phalangeal ligament.s  of  the  three  outer  toes  and  transverse 
metatarsal  ligament ;  insertion,  with  the  adductor  obliquus 
hallucis  into  the  outer  side  of  the  first  phalanx  of  the  great  toe  ; 
action,  adducts  the  great  toe;  nerve,  external  plantar. 

Flexor  brevis  minimi  digiti :  origin,  base  of  the  fifth  metatar- 
sal and  sheath  of  the  peroneus  longus  tendon  ;  insertion,  outer 
side  of  the  base  of  the  first  phalanx  of  the  little  toe.  often  to 
the  head  of  the  fifth  metatarsal ;  action,  flexes  and  abducts 
the  first  phalanx  ;   nerve,  external  plantar. 

Fourth  layer. 

Dorsal  interossei  (four)  :  origin,  each  by  two  heads  from  the 
adjacent  sides  of  the  metatarsal  bones  ;  insertion,  tendinous  into 
the  bases  of  the  first  phalanges  and  aponeuroses  of  the  common 
extensor  ;  action,  flexes  the  first  phalanx,  extends  the  last  two, 
abducts  toes  from  an  imaginary  line  passing  through  the  center 
of  the  second  toe ;  nerves,  external  plantar  and  anterior  tibial. 

Plantar  interossei  (three)  :  origin,  single  heads  from  the  base 
and  inner  sides  of  the  shaft  of  the  third,  fourth,  and  fifth 
metatarsal  bones  ;  insertion,  inner  sides  of  the  bases  of  the 
phalanges  and  extensor  aponeuroses  of  the  same  toes;  action, 
flex  and  extend  as  above,  and  adduct  the  toes  toward  a  line 
passing  through  the  middle  of  the  second  toe  ;  nerve,  ex- 
ternal plantar. 

THE    VASCULAR    SYSTEM. 

What  is  the  pericardium? 

A  closed  fibro-serous  sac  of  conical  form,  its  apex  surround- 
ing the  great  ves!?els  for  about  two  inches  above  their  origin, 
its  base  downward,  attached  to  the  central  tendon  of  the  dia- 
phragm. The  outer  fibrous  coat  is  continued  as  tubular  pro- 
longations, lost  upon  the  external  coats  of  the  roots  of  all  the 
great  vessels  except  the  inferior  vena  cava,  and  is  finally  trace- 
able as  continuous  with  the  deep  layer  of  tlie  cervical  fascia  ; 
the  serous  coat  lines  the  sac,  forming  a  ])(rrl<'t(il  layer,  and  is 
reflected  over  the  heart  and  great  vos.sels,  forming  a  visceral 
layer  ;  its  function   is  the  secretion  of  a  thin  fluid  in  sufficient 


182  ESSENTIALS  OF  HUMAN   ANATOMY. 

amount  to  moisten  the  surfaces,  thus  lessenin<r  friction  during 
the  heart  s  movements. 

Describe  the  heart  and  its  position. 

It  is  a  hollow,  conical  muscle,  with  four  distinct  cavities, 
situated  obliquely  between  the  lungs,  the  base  upward,  back- 
ward, and  to  the  right,  the  apex  '^  (Fig.  101)  downward,  for- 
ward, and  to  the  left,  corresponding  to  the  fifth  intercostal 
space,  three  and  a  half  inches  from  the  middle  line  of  the 
sternum.  The  upper  limit  of  the  heart  is  represented  by  a  line 
passing  from  the  lower  border  of  the  second  left  costal  cartilage 
to  the  upper  border  of  the  third  on  the  right  side.  The  anricido- 
ventricular  groove  is  shown  by  a  line  drawn  obliquely  from  the 
sternal  end  of  the  third  left  cartilage  to  the  upper  border  of 
the  sternal  end  of  the  seventh  on  the  right  side.  The  right 
border  is  represented  by  a  line  from  the  third  right  to  the 
seventh  right  chondro-sternal  articulation,  arching  outward  one 
and  a  half  inches  from  the  middle  line  ;  the  lovser  limit,  by  a 
line  from  the  seventh  right  articulation  to  the  apex  in  the  fifth 
space  ;  the  le/t  border,  from  the  second  left  cartilage  to  the 
apex. 

The  pulmonary  valve  is  covered  by  the  sternal  end  of  the 
third  left  cartilage  ;  the  aortic  valve  is  a  little  below  and  inter- 
nal to  this,  behind  the  sternum,  on  a  level  with  the  third  space, 
between  the  mid-sternal  and  left  sternal  lines.  The  auriculo- 
ventricular  openings  are  lower  than  the  arterial.  The  mitral  is 
at  the  sternal  end  of  the  third  left  space  (behind  the  sternal 
end  of  the  fourth  left  costal  cartilage.  Quain).  Draw  a  hori- 
zontal line  between  the  two  sternal  ends  of  the  fifth  cartilages ; 
where  this  line  intersects  the  one  marking  the  auriculo-ven- 
tricular  groove  is  the  spot  indicating  the  tricuspid  valve,  behind 
the  sternum. 

Give  the  size  and  weight  of  the  heart. 

In  adults  it  measures  five  inches  long,  three  and  one-half 
broad,  and  two  and  one-half  thick ;  weighs  in  the  male  ten  to 
twelve  ounces,  in  proportion  to  the  body  1  to  169 ;  in  females, 
eight  to  ten  ounces,  1  to  149. 

What  are  the  four  cavities  of  the  heart  called? 

The  right  auricle^  and  the  right  ventricle*,  the  left  auricle 
and  the  left  ventricle,  separated  by  a  longitudinal  septum — indi- 


THE  VASCULAR  SYSTEM.  183 

cated  externally  in  front  and  behind  by  the  interventricular 
grooft'ii — dividing  the  heart  into  lateral  halves,  the  right  or 
venous  heart,  the  left  or  arterial  heart  ;  an  oblique  anricnlo- 
veatricidar  groove  on  the  exterior  corresponds  to  the  division 
between  the  auricles  and  the  ventricles. 

Describe  the  right  auricle. 

Larger  than  the  left  auricle,  with  a  capacity  of  about  two 
fluid  ounces;  its  walls  are  about  one  line  thick;  the  venous 
blood  is  poured  in  by  the  superior  ^  and  the  inferior  venae 
cavae  '^  and  the  coronary  sinus  ;  note  the  following  points : 

The  sinus  or  atrium,  the  large  quadrangular  cavity  between 
the  two  venae  cavae  ;  the  appendix  auricidse,  a  conical  pouch 
with  dentated  edge,  projecting  forward  to  the  left  over  the  root 
of  the  aorta  *^ ;  openings  of  the  two  venae  cavae,  also  that  of  the 
coronary  sinus  ^",  its  orifice  guarded  by  a  semicircular  fold 
called  the  coronary  valve — sometimes  two  unequal  segments  are 
found;  the  tubercle  of  Lou-cr'',  a  small  projection  on  the  right 
upper  wall  directing  blood  from  the  superior  cava  toward  the 
auriculo- ventricular  opening,  not  marked  in  man  ;  the  foramina 
Thehesii,  the  mouths  of  numerous  minute  veins  returning 
blood  from  the  heart-muscle  ;  openings  of  a  few  anterior  cardiac 
veins;  the  semilunar  Eustachian  valve ^'  hety^e^n  the  anterior 
margin  of  the  inferior  vena  cava  and  auriculo-ventricular  open- 
ing— it  is  larger  in  the  fetus,  serving  to  direct  the  blood  of  the 
inferior  cava  through  the  foramen  ovale;  the  fossa  ovalis^\  an 
oval  depression  at  the  lower  part  of  the  auricular  septum,  the 
site  of  the  oval  foramen  in  the  fetus  ;  the  aniiulus  oralis,  the 
prominent  margin  of  the  fossa  ovalis  ;  the  musculi  pectinati, 
small  prominent  muscular  columns  running  across  the  inner 
surface  of  the  appendix  and  adjoining  wall  r^f  the  sinus  ;  the 
oval  auriculo-ventrlcidar  orifice,  about  one  inch  in  diameter, 
communicating  with  the  right  ventricle,  its  margins  formed  by 
a  fibrous  ring  covered  by  the  lining  membrane,  and  guarded  by 
the  tricuspid  valve. 

Describe  the  right  ventricle. 

Tt  is  triangular,  with  the  apex  downward,  not  quite  reaching 
that  of  the  heart,  forming  with  the  right  auricle  the  anterior, 
rather  than  the  right  side  of  the  heart ;  its  capacity  is  about 


184  ESSENTIALS  OF  HUMAN  ANATOMY. 

three  fluid  ounces ;  it  presents  the  following  points  for  ex- 
amination : 

Above  is  the  conical  prolongation  called  the  conits  (irten'osus, 
from  which  opens  the  piiInioiK(ri/  artenj  placed  to  the  left  of 
the  auriculo-ventricular  orifice,  which  is  surrounded  by  a  fibrous 
ring;  the  pulmonary  semihoiar  vfdces  guard  the  pulmonary 
orifice;  the  fricusjnd  valve^,  ^',  ^",  formed  of  three  triangular 
segments — the  largest  on  the  left  side — by  a  reduplication 
of  the  lining  membrane  with  interposed  fibrous  tissue ;  the 
flaps  are  called  the  left,  ric/ht,  and  posterior  or  septal ;  they 
are  prevented  from  being  forced  into  the  auricle  by  the 

Chordde,  tendiaese^",  fine  tendinous  cords  stretching  from  (1) 
the  columnge  carnese  to  the  attached  margins  of  the  leaflets, 

(2)  to  their  centers,  and  (3)  to  their  free  margins. 

The  cohminse  carnese'^',  three  varieties  of  muscular  columns, 
(1 )  simple  ridges,  (2)  bands  attached  by  both  extremities,  and 

(3)  two  muscnU  j^^^pdlares,  muscular  eminences  from  which 
arise  the  chordae  tendineae.  The  anterior  muscle  is  larger  and 
more  constant  than  the  posterior,  which  may  be  represented  by 
two  or  three  smaller  muscles. 

The  three  pulmonari/  semilunar  valves*^  two  anterior,  a  right 
and  a  left,  and  one  posterior,  formed  by  a  reduplication  of  the 
lining  membrane  with  interposed  fibrous  tissue,  with  their  free 
margins  strengthened  by  a  bundle  of  fibrous  tissue,  whose  fibers 
radiate  from  a  fibro-cartilaginous  nodule — corpus  Arantii — to 
all  parts,  except  to  two  narrow  lunated  portions  ( lunulde)  on 
either  side  of  the  nodule,  which  are  forced  into  contact  when 
the  valves  are  closed ;  above  and  behind  each  valve  is  a  dilata- 
tion, the  sinus  of  Valsalva. 

Describe  the  left  auricle. 

Resembles  the  right  in  having  a  principal  cavity  or  sinus 
and  an  appendix,  but  its  walls  are  thicker,  measuring  about 
one  and  one-half  lines.   The  following  points  should  be  studied  : 

The  openings  of  the  pulmonary  veins,  usually  four  in  number, 
two  emptying  into  the  right  and  two  into  the  left  side ;  fre- 
quently the  latter  terminate  by  a  common  opening. 

The  oval  auriculo-ventricular  opening,  surrounded  by  a  fibrous 
ring,  smaller  than  the  right ;  the  mnsculi  pectinati  fewer  and 
smaller  than  on  the  right  side  ;  a  depression  over  the  site  of 
the  fossa  ovalis  of  the  right  auricle. 


THE   VASCULAR  SYSTEM. 


185 


Describe  the  left  ventricle. 

Larger  and  more  conical  than  the  right,  it  forms  but  little 
of  the  anterior  surface,  most  of  the  inferior  surface  and  all  the 
apex"  of  the  heart,  its  walls  being  three  times  as  thick  as 
those  of  the  right  ventricle ;  its  inner  surface  presents,  for 
examination  : 

The  circular  aortic  opening^  with  the  usual  fibrous  ring,  in 
front  and  to  the  right  of  the  auriculo-ventricular  opening,  be- 
tween tliem  intervenes  one  of  the  segments  of  the  mitral  valve, 
its  mouth  being  guarded  by  three  semilunar  valves  ;  the  mitral 
valve,  composed  of  two  irregular  segments — the  larger  in  front 


Tig.  101.— The  heart,  with  right  auricle  and  right  ventricle  laid  open  (Leidy). 

— similar  to  those  of  the  tricuspid  valve,  but  larger  and  thicker, 
the  leaflets  being  provided  with  chordjie  tendine^ie,  whose  mode 
of  attachment  is  identical  with  those  of  the  right  side.  The 
firmiliinar  aortic  valves  resemble  those  of  the  pulmonary  artery, 
but  are  larger  and  stronger ;  two  are  anterior  and  one  poste- 


186  ESSENTIALS  OF  HUMAN   ANATOMY. 

rior  in  the  fetal  condition.  l)ut  in  the  adult  one  is  anterior  and 
two  are  posterior,  right  and  left  ;  the  stiluses  of  V(ihah:a  are  like 
those  of  the  pulmonary  artery,  and  are  found  behind  the  aortic 
valves. 

The  columnse  earnest  are  more  numerous,  but  smaller  than  on 
the  right  side,  while  there  are  only  two  musculi papillares. 

What  is  the  endocardium? 

The  delicate  lining  membrane  of  the  heart  continuous  with 
the  intima  of  the  great  vessels,  by  its  reduplications  forming 
the  various  valves. 

Describe  the  he  art- structure. 

It  consists  of  striated  anastomosing  muscular  fibers  taking 
origin  from  the  fibrous  rings  surrounding  the  aortic,  pulmo- 
nary, and  auriculo-ventricular  openings,  disposed  in  the  auricles 
in  a  deep  layer  composed  of  looped  and  annular  fibers,  and  a 
superficial  transverse  layer ;  in  the  ventricles  numerous  layers 
have  been  described,  the  deepest  of  which  run  circularly,  the 
more  superficial  spirally,  curving  round  the  apex  to  form  the 
whorl  or  vortex,  those  fibers  from  in  front  curving  around  to 
enter  posteriorly,  and  vice  versa  ;  the  most  superficial  fibers, 
especially  those  behind,  pass  across  the  septum  from  one  ven- 
tricle to  the  other. 

The  Arteries. 

What  are  the  arteries? 

(Cylindrical,  tubular  vessels  conveying  blood  from  both  ven- 
tricles to  all  parts  of  the  body  ;  the  blood  they  carry  is  called 
arterial,  except  in  the  case  of  the  pulmonary  artery  conveying 
venous  blood  to  the  lungs,  and  the  four  pulmonary  veins  re- 
turning arterial  blood  to  the  left  auricle,  constituting  the  lesser 
or  pulmonic  circulation,  while  the  aorta  arising  from  the  left  ven- 
tricle carrying  blood  to  the  body  generally,  and  the  veins  return- 
ing it,  finally  emptying  by  the  two  venae  cavae  into  the  right 
auricle,  form  the  greater  or  systemic  circulation.  In  their  dis- 
tribution the  arteries  freely  communicate  with  one  another, 
the  large  branches  as  well  as  the  small  forming  what  are  called 
collateral  anastomoses  or  inosculations,  permitting  the  establish- 
ment of  a  collateral  circulation  after  obliteration  of  a  main 
artery. 


THE   ARTERIES. 


187 


Describe  the  structure  of  the  arteries. 

They  possess  tliree  coats:  (Ij  an  interiutl  (serous)  or  intima  ; 
(2)  a  middle  (^iiiedi(f),  composed  in  small  vessels  almost  purely 
of  circular  muscular  fibers,  in  the 
larger  chiefly  of  yellow  elastic  tissue  ; 
this  prevents  the  arteries  from  col- 
lapsing when  cut  across ;  (3)  an  ex- 
teriud  (^adventitial,  composed  of  con- 
nective tissue.  Every  vessel,  except 
the  intracranial  vessels,  is  included 
with  its  vein  or  veins  in  a  fibro-areolar 
sheath. 


How  are  the  arteries  nourished  and 
their  caliber  regulated? 

The  larger  vessels  are  supplied  by 
minute  vasa  vasormn,  blood-vessels 
distributed  in  a  fine  network  to  their 
external  coats ;  while  intricate  nerve- 
networks  (plexuses),  chiefly  derived 
from  the  sympathetic,  partly  from  the 
spinal  system,  supply  the  two  outer 
coats  of  the  large  vessels — the  smaller 
are  usually  supplied  only  with  single 
filaments. 

What  are  capillaries? 

The  intermediate  vessels  between 
the  arteries  and  veins,  disposed  in  the 
form  of  a  network,  of  an  average  di- 
ameter of  one-three-thousandths  of  an 
inch,  formed  of  a  fine  transparent  layer 
of  endothelial  cells  united  by  a  ce- 
ment-substance. 

Describe  the  pulmonary  artery. 

It  is  a  wide  vessel  conveying  ven- 
ous 1)100(1  from  the;  right  ventric](;  to 
the  lungs,  about  two  irich(;s  long,  and 
springs,  in  front  of  the  aort;i.  from  the;  l(;f"t  side  of  the  base  of 
the  right  V('ntri(;l(!,  lying  within  tin;  pericardium,  passing  ob- 
liquely U)  the  left,  upward  and  backward,  dividing  at  the  under 


Fin.  10'_'.  -  The  aorta'  and 
tliuir  branches  (Leidy). 


188  ESSENTIALS  OF  HUMAN   ANATOMY. 

surface  of  the  aortic  arcli  into  a  riijlif  and  a  left  pulmonary 
artery^  the  former  the  longer;  each  vessel  pierces  the  pericar- 
dium and  passes  horizontally  outward  to  its  respective  lung, 
where  it  divides  into  two  main  branches,  one  of  those  of  the 
right  subdividing  to  supply  the  third  lobe  ;  these  vessels  sub- 
divide to  terminate  in  the  pulmonary  capillaries. 


Describe  the  aorta',  \^  (Fig.  102). 

This,  the  main  trunk  of  the  systemic  arteries,  arises  from  the 
upper  part  of  the  left  ventricle,  ascends  and  then  arches  back- 
ward to  the  left  over  the  root  of  the  left  lung  to  descend  within 
the  thorax  on  the  left  side  of  the  vertebral  column,  entering 
the  abdominal  cavity  by  the  aortic  opening**  behind  the  dia- 
phragm, where  it  terminates  opposite  the  fourth  lumbar  verte- 
bra in  the  two  common  iliac  arteries ^^;  the  aorta  is  divided  for 
convenience  of  study  into  the  ascending  aorta,  arch  of  the  aorta,^ 
thoracic'^,  and  abdominal  aorta^.  The  branches  of  each  sub- 
division are : 

From  the  ascending  aorta  <  Two  coronary, 

i  Innominate, 
From  arch  of  the  aorta     I  Left  common  carotid, 

(  Left  subclavian. 

r  Pericardiac,  Posterior  mediastinal. 
From  the  thoracic  aortal  Bronchial^,    Intercostal",^^, 

(^  Esophageal 


10 


From  the  abdominal  aorta  are  three  groups  with  three  in  each : 

r  Gastric  '^, 
Celiac  axis  ^  Hepatic  ^^, 
Visceral  ^  ( Splenic  '^. 

I    Superior  mesenteric  ^^, 

1^  Inferior  mesenteric  ^'. 

(  Two  renal  "^°, 
Glandular       I   Two  suprarenal  *'', 

(^  Two  spermatic  ''^",  or  ovarian. 

r  Ten  lumbar  '^'\ 
Parietal  I   Two  inferior  phrenic  '', 

(    One  middle  sacral  ^\ 


THE   ARTERIES.  189 

Give  the  relations  of  the  aorta  in  the  thorax. 

Ascending  aorta  :  a)d<nior^  pulmonary  artery,  right  auricular 
appendix,  pericardium ;  posftrrlor^  right  pulmonary  artery, 
right  bronchus,  left  auricle,  pericardium  ;  right  side,  superior 
vena  cava,  right  auricle  ;  left  side,  pulmonary  artery. 

Arcli  of  tJie  aorta  :  anterior,  pleura  and  lungs,  remains  of 
the  thymus  gland,  left  pneumogastric  nerve,  left  phrenic  nerve, 
left  superior  cardiac  nerves,  left  superior  intercostal  vein ; 
jjosterior,  trachea,  deep  cardiac  plexus,  esophagus,  thoracic 
duct,  left  recurrent  nerve  ;  above,  left  innominate  Tein,  innomi- 
nate artery,  left  carotid,  left  subclavian  ;  beloic,  bifurcation  of 
the  pulmonary  artery,  ligamentum  arteriosum,  superficial  car- 
diac plexus,  left  recurrent  nerve,  left  bronchus,  bronchial 
glands. 

Thoracic  aorta:  anterior,  left  pulmonary  artery,  left 
bronchus,  pericardium,  esophagus  (below)  ;  jxjsterior,  vertebral 
column,  vena  azygos  minor ;  right  side,  esophagus,  vena  azygos 
major,  thoracic  duct,  right  pleura  and  lung ;  left  side,  left 
pleura  and  lung,  esophagus  (below j. 

Describe  the  coronary  arteries. 

The  right  arises  from  the  aorta  above  the  free  margin  of  the 
anterior  semilunar  valve,  passes  in  the  groove  between  the 
right  auricle  and  ventricle  to  the  posterior  interventricular 
groove,  where,  dividing  into  two  branches,  one  continues 
onward  anastomosing  with  the  left  coronary,  the  other  descends 
along  the  interventricular  groove  to  the  apex  of  the  heart, 
anastomosing  with  the  descending  branch  of  the  left  coronary  ; 
the  left  coronarij.  the  larger,  arises  above  the  free  edge  of  the 
left  posterior  semilunar  valve,  passes  forward  between  the  pul- 
monary artery  and  the  left  appendix,  thence  obliquely  to  the 
anterior  interventricular  groove,  where  it  divides,  one  branch 
passing  around  to  join  the  right  vessel,  the  other  descending  in 
the  groove  to  anastomose  at  the  apex  with  the  descending 
branch  of  the  right  vessel. 

Describe  the  innominate  artery  *. 

Arising  from  the  commencement  of  the  arch  of  the  aorta,  it 
is  from  one  and  a  half  to  two  irjches  long  and  bifurcates  at  the 
upper  border  of  the  right  sterno-clavicular  articulation  into  the 
right  common  carotid''  and  subclavian";  sometimes  it  sends  off 


190  ESSENTIALS  OF  HU^FAN   ANATOMY. 

a  tliyroldeu  una  branch  ;  occasionally  no  innominate  exists,  the 
right  carotid  and  subclavian  springing  directly  from  the  aorta. 
Rdations  of  the  innominate  artery  are  :  in  front,  sternum, 
sterno-hyoid  and  sterno-thyroid  muscles,  remains  of  the  thy- 
mus gland,  left  innominate  vein,  right  inferior  thyroid  vein, 
inferior  cervical  cardiac  branch  of  the  right  pneumogastric 
nerve  ;  right  side,  right  innominate  vein,  right  pneumogastric 
nerve,  pleura;  left  side,  remains  of  the  thymus  gland,  left 
carotid  artery,  left  inferior  thyroid  vein,  trachea;  behind, 
trachea. 

Describe  the  common  carotid^,  ^ 

The  right  common  carotid  artery^  arises  opposite  the  right 
sterno-clavicular  joint  from  the  innominate,  the  left  from  the 
summit  of  the  aortic  arch.  In  the  neck  their  course  corre- 
sponds to  a  line  passing  from  the  sterno-clavicular  joint  to  a 
point  midway  between  the  mastoid  process  and  the  angle  of 
the  lower  jaw  ;  below,  the  trachea  only  separates  them,  above 
there  is  a  wide  interval ;  a  common  sheath  of  deep  fascia  en- 
closes the  internal  jugular  vein,  the  pneumogastric  nerve 
(posterior  to  both)  and  artery,  enumerated  from  icithout 
inicard,  while  upon  the  sheath  lies  the  branch  of  the  first 
and  second  cervical  nerves  (descendens  cervicalis). 

The  anterior  relations  of  the  vessel  for  the  most  of  its  course 
are  the  anterior  margin  of  the  sterno-cleido-mastoid  muscle,  while 
about  its  middle  it  is  crossed  by  the  omo-hyoid  muscle,  the 
anterior  jugular  and  middle  th^^roid  veins,  while  above  the 
omo-hyoid  muscle,  the  stern o-mastoid  artery,  and  the  superior 
thyroid  vein  cross  it ;  at  the  lower  part  of  the  neck  the  right 
internal  jugular  vein  diverges  from  the  artery,  but  the  left 
often  crosses  the  lower  part  of  the  corresponding  artery  ;  it  is 
also  in  relation  anteriorly  to  the  sterno-hyoid,  sterno-thyroid, 
and  platysma  muscles,  to  the  deep  and  superficial  fasciae  and 
skin.  Internally  lie  the  trachea,  the  thyroid  gland,  recurrent 
laryngeal  nerve,  inferior  thyroid  artery,  larynx,  and  pharynx. 
Posteriorly  are  the  longus  colli  and  rectus  capitis  anticus 
major  muscles,  sympathetic  and  recurrent  laryngeal  nerves, 
and  inferior  thyroid  artery.  Opposite  the  upper  border  of  the 
thyroid  cartilage  each  vessel  divides  into  the  internal  ?Lnd.  the  ex- 
ternal carotid.     The  common  carotid  arteries  have  no  branches. 

The  left  common  carotid  artery  has,  in  addition  to  the  above 


THE   ARTERIES.  191 

description,  a  fhoracic  portion  which  presents  the  following 
relations:  in  front,  sterno-hyoid  and  sterno-thyroid  muscles, 
left  innominate  vein,  remains  of  the  thymus  gland  ;  behind^ 
trachea,  esophagus,  thoracic  duct,  left  subclavian  artery,  its 


Fig.  103.— The  arteries  of  the  face  and  scalp  (Leidy). 

thoracic  portion  ;  infprnall)/,  innominate  artery,  inferior  thyroid 
veins,  and  remains  of  the  thymus  gland  ;  externally,  left  pneumo- 
gastric  nerve,  left  pleura  and  lung,  and  left  subclavian  artery. 

Name  the  branches  of  the  external  carotid  artery,  with  their 
subdivisions. 

1.  Superior  tlii/roixV  (Fig.  103),  arising  below  the  greater 
cornu  of  the  hyoid^bone;  its  branches  are: 

Muscular,  Hyoid,  Superior  laryngeal, 

Superficial  descending  (sterno-mastoid),    Crico-thyroid. 

2.  /y/y/y/zr// ;iris(!s  between  the  superior  thyroid  and  the  facial 
running  })eneath  the  hyoglossus  muscle  to  the  under  surface  of 
the  tongue  ;  its  branches  are  : 

Ilyoid,       Dorsalis   linguic,       Sublingual,       Ranine. 


192  ESSENTIALS  OF  HUMAN  ANATOMY. 


3.   Facial^ arises  just  above  the  lingual  to  cross  the  lower  jaw 
just  anterior  to  the  masseter  muscle ;  its  branches  are  : 

Muscular '^ 
Inferior  labial  **, 
Inferior  coronary^, 


Muscular, 
Inferior  or  ascend- 

Cervical  ^   m      '^n  '  Facial 

lonsillar, 

Submaxillary, 

Submental  \ 


Superior  coronary 
Lateralis  nasi ", 


Angular  ^'\ 


4.  OccijyitaP^  arises  posteriorly  opposite  the  facial,  lies  in 
the  occipital  groove  of  the  temporal  bone  ;  its  branches  are  : 

Muscular,  Sterno-mastoid,  Mastoid,       Auricular, 

Princeps  cervicis.    Meningeal,  Terminal  or  Cranial. 

5.  Posterior  auricular  ^^  arises  opposite  the  styloid  process, 
ascends  beneath  the  parotid  gland  to  the  groove  between  the 
cartilage  of  the  ear  and  the  mastoid  process ;  its  branches  are  : 

Muscular,  Parotid,  Stylo-mastoid, 

Auricular,  Mastoid  or  Occipital. 

6.  Ascending  pharyngeal^  running  between  the  carotid  and 
the  side  of  the  pharynx,  its  branches  being  very  numerous 
and  inconstant,  and  divided  into  three  sets — . 

Pharyngeal,  Meningeal,  and  Prevertebral. 

7.  Svperficial  femp07'al,  terminal  branch,  commences  in  the 
substance  of  the  parotid  gland,  crosses  the  root  of  the  zygoma, 
two  inches  above  which  it  divides  into  the  anterior  '^*  and  ^poste- 
rior'^^  femjwral;  its  other  branches  are  : 

Parotid,         Articular,         Masseteric,  Anterior  auricular, 

Transverse  facial  ^°,  Middle  temporal  ^^,  and  Orbital  ^'^ 

8.  Internal  maxillari/^,  the  larger  terminal  branch,  passes 
inward  at  right  angles  to  the  carotid  at  fhe  inner  side  of  the 
neck  of  the  condyle  of  the  lower  jaw  ;  it  is  divided  into  three 
portions :  (1)  maxillary^  (2)  pterygoid,  and  (3)  spheno-maxil- 
lary  (Fig.  104)  : 

(1)  Deep  auricular.  Small  meningeal, 

Tympanic,  (  Mylo-hyoid, 

Middle  meningeal.  Inferior  dental  X  Incisor, 

(  Mental. 


THE   ARTERIES. 

(2)  Deep  temporal  -I        .     •  '    at 

^  -^  r         1  ^  posterior,  iMasseteric, 

Pterygoid,  Buccal. 

(3)  Alveolar,  Vidian. 
Infraorbital,  Pterygo-palatine, 
Superior  or  Descending  Nasal  or  Spheno-palatine. 

palatine. 


193 


/mJJ/e  Menivffeal 
^Icwnyca    Parva 

Ti/m/ianic- 
l-nfiritT  Denial- 


Fig.  104.— Plan  of  the  branches  of  the  internal  maxillary  artery  (Gray). 

Relations  of  the  external  carotid  arte)?/ :  antero-external, 
skin,  superficial  and  deep  fascia,  platysma,  anterior  border  of 
the  sterno-mastoid,  hypoglossal  nerve,  lingual  and  facial  veins, 
posterior  belly  of  the  digastric  and  stylo-hyoid  muscles,  parotid 
gland  with  branches  of  the  facial  nerve,  temporo-maxillary 
vein,  lymphatic  glands,  and  internal  carotid  artery  ;  posterior, 
superior  laryngeal  nerve,  stylo-glossus  and  stylo-pharyngeus 
muscles,  glosso  pharyngeal  nerve,  pharyngeal  branch  of  the 
pneumogastric,  stylo-hyoid  ligament  and  parotid  gland ;  the 
latter  six  of  this  group  separate  the  external  from  the  internal 
carotid  artery  ;  internal,  hyoid  bone,  pharynx,  superior  laryn- 
geal nerve,  parotid  gland,  ramus  of  the  jaw,  stylo-maxillary 
ligament. 

Describe  the  internal  carotid  artery. 

It  runs  in  front  of  the  tran.^ verse  processes  of  the  three 
upper  cervical  vertebrae  in  contact  with  the  pharynx  and  ton- 
sil to  the  carotid  canal  of  the  temporal  bone,  enters  the  skull, 
passes  through  the  cavernous  sinus  and  pierces  the  dura  mater 
near  the  anterior  clinoid  process,  where  it  divides  into  the  ante- 
rior and  the  middle  cerebral  arteries. 

13 


194 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Name  its  branches. 

Tympanic  (deep),  from  the  artery  in  the  carotid  canal,  anas- 
tomosing with  the  tympanic  branch  of  the  internal  maxillary, 
stylo-mastoid,  and   Vidian  arteries. 

Arterise  receptacull,  small  vessels  supplying  the  cavernous 
and  inferior  petrosal  sinuses,  pituitary  body,  and  Gasserian 
ganglion  ;  some  to  the  dura  mater  anastomosing  with  the  mid- 
dle meningeal  are  called  the  anterior  meningeal. 

Ophthalmic.,  from  the  cavernous  portion,  enters  the  orbit  by 
the  optic  foramen,  dividing  at  the  inner  angle  of  the  eye  into 
two  terminal  divisions,  the  frontal  and  the  nasal ;  its  branches 
are  : 


Orbital 
group 


Lacrimal, 

Supraorbital, 

Posterior  ethmoidal, 

Anterior  ethmoidal, 

Palpebral, 

Frontal, 

Nasal. 


Ocular 
group 


[  Muscular, 

I    Anterior  ciliary, 

I    Short  ciliary. 

Long  ciliary, 

Arteria  centralis  re- 
tinae. 


Anterior  cerebral  passes  forward  in  the  great  longitudinal 
cerebral  fissure,  and  communicates  with  its  fellow  by  the  ante-, 
rior  communicating  artery,  a  vessel  about  two  lines  long. 

Middle  cerebral,  the  largest  branch,  is  lodged  in  the  Sylvian 
fissure  and  divides  into  the  antero-lateral  ganglionic  branches^ 
which  enter  the  anterior  perforated  space  ;  the  external.,  inferior, 
and  ascending  frontal,  and  the  ascending  parietal ,  supplying  the 
parts  indicated ;  the  parieto-temporal ^  to  the  convolutions  around 
the  horizontal  limb  of  the  Sylvian  fissure. 

Anterior  choroid^  to  the  hippocampus  major,  corpus  fim- 
briatum,  velum  interpositum,  and  choroid  plexus. 

Posterior  commnnicating  runs  back  to  anastomose  with  the 
posterior  cerebral,  a  branch  of  the  basilar  artery. 

Describe  the  circle  of  Willis. 

It  consists  of  a  vascular  anastomosis  at  the  base  of  the  brain, 
between  the  branches  of  the  carotids  and  basilar  artery,  whereby 
pressure  on  or  blocking  of  any  two  of  the  main  trunks  will 
not  prevent  both  sides  of  the  brain  from  receiving  a  supply  of 
blood.  Its  formation  is  as  follows  :  the  two  vertebrals  by 
their  junction  form  the  basilar,  which  divides  into  two  paste- 


THE  ARTERIES.  195 

rior  cerehrals,  these  latter  being  connected  with  the  back  part 
of  the  internal  carotids  on  each  side  by  a  poster if/r  commimi- 
cating^  while  the  anterior  terminals  of  the  carotids,  viz.,  the 
anterior  cerebral  on  each  side,  are  connected  in  front  by  the 
short  anterior  communicating  artery  before  mentioned. 

Describe  the  subclavian  artery. 

On  the  right  side  it  springs  from  the  innominate,  on  the  left 
directly  from  the  aortic  arch.  It  is  divided  into  three  portions, 
viz.,  that  internal  to  the  anterior  scalene  muscle,  that  behind 
the  muscle,  and  that  external  to  the  scalene,  this  muscle  inter- 
vening between  the  artery  and  the  subclavian  vein  ;  it  ceases  to 
be  called  subclavian  at  the  lower  border  of  the  first  rib.  then 
being  termed  axillary.  The  branches  arise  from  the  first  por- 
tion, except  the  right  superior  intercostal,  which  comes  from 
the  second;  the  posterior  scapular  or  suprascapular  often  comes 
from  the  third  portion. 

Relations  of  the  right  subclavian  artery:  first  portion;  anterior^ 
skin,  superficial  and  deep  fasciae,  platysma,  clavicular  origin  of 
the  sterno-mastoid.  the  sterno-hyoid,  and  sterno-thyroid  muscles, 
beginning  of  right  innominate  vein,  internal  jugular  and  verte- 
bral veins,  pneumogastric,  cardiac,  and  phrenic  nerves  ;  poste- 
rior, recurrent  laryngeal  nerve,  sympathetic,  apex  of  the  lung 
and  pleura,  longus  colli,  neck  of  the  first  rib;  inferiorhj  are 
the  pleura  and  lung. 

Second  portion  ;  anterior,  skin,  two  layers  of  fascia,  platysma, 
sterno-mastoid,  phrenic  nerve,  scalenus  anticus,  subclavian  vein; 
posterior,  pleura,  lung,  and  scalenus  medius ;  above  is  the 
brachial  plexus,  and  below,  the  pleura  and  lung. 

Third  portion  ;  anterior,  skin,  two  layers  of  fascia,  platysma, 
descending  branches  of  the  cervical  plexus,  nerve  to  the  sub- 
clavius,  subclavius  muscle,  suprascapular  artery  and  vein, 
external  jugular  and  transverse  cervical  veins,  clavicle  ;  behind 
is  the  scalenus  medius  ;  above  is  the  brachial  plexus,  omo-hyoid 
muscle ;  belov)  is  the  posterior  groove  on  the  first  rib. 

Relaiions  of  the  first  portion  of  the  left  subclavian  artery :  in 
front,  left  pleura  and  lung,  left  carotid  artery,  left  internal 
jugular,  vertebral,  and  innominate  veins,  vagus,  phrenic,  and 
cardiac  nerves  ;  superfici(dly,  the  sternohyoid,  sterno-thyroid, 
and  sterno-mastoid  muscles  ;  internally,  trachea,  esophagus,  and 
thoracic  duct ;  externally,  pleura ;  behind,  esophagus,  thoracic 


196  ESSENTIALS  OF  HUMAN    ANATOMY. 

duct,  inferior  cervical  ganglion  of  the  sympathetic,  and  the 
longus  colli  separating  .it  from  the  vertebral  column. 

The  hranches  are  : 

Vertfhral.  which  passes  through  the  foramina  in  the  cervical 
transverse  processes  except  that  of  the  seventh,  enters  the 
skull  through  the  foramen  magnum,  joining  its  fellow  at  the 
lower  border  of  the  pons  A^arolii  to  form  the  basihr  artery ; 
its  branches  are : 

(  Lateral  spinal,  (  Anterior  spinal, 


^      •    1  j   Muscular.  ^,      .  , 

Cervical  <   t>    .     •  •       Lranial 

I    rosterior       menin- 


Posterior  spinal. 
Posterior      inferior 
cerebellar. 


I       geal. 
Basilar,  formed  by  the  vertebrals,  gives  off  the  following: 

Transverse.  Superior  cerebellar, 

Internal  auditory.  Posterior  cerebral. 

Anterior,  Inferior  cerebellar. 

Thyroid  axis  divides  almost  at  once  into  the 

1.  Inferior  thyroid,  to  the  same  named  gland,  giving  off  the 

Inferior  laryngeal,  Esophageal, 

Tracheal,  Muscular.  Asc-ending  cervical. 

2.  Svprascapidar.  chiefly  to  the  shoulder-joint  and  supra- 
spinous fossa  ;  it  anastomose?  with  the  acromio-thoracic,  pos- 
terior circumflex,  the  posterior  and  subscapular  arteries. 

3.  Transversalis  colli,  larger  than  the  preceding,  passes  trans- 
versely outward  to  the  trapezius,  beneath  which  it  divides  into 
the 

Superficial  cervical.  Posterior  scapular. 

Internal  mammary  arises  from  the  under  surface  of  the  first 
portion,  opposite  the  thyroid  axis,  descends  behind  the  costal 
cartilages  half  an  inch  from  the  sternum  to  the  sixth  interspace, 
where  it  divides  into  the  muscido-phrenic  and  the  superior  epi- 
gastric., the  latter  anastomosing  with  the  deep  epigastric  and 
its  fellow ;  the  branches  are  : 

Superior  phrenic,  or  Anterior  intercostal. 

Comes  nervi  phrenici,  Perforating. 

Mediastinal,  Lateral  infracostal, 

Pericardiac,  Musculo-phrenic. 

Sternal,  Superior  epigastric. 

Superior  intercostal  passes  in  front  of  the  neck  of  the  first 


The  arteries.  197 

rib,  giving  off  the  deep  cervical,  and  two  Intercostals  which  have 
posterior  muscular  and  sjiiiial  branches. 

Profunda  cervicis  supplies  the  posterior  cervical  muscles  and 
anastomoses  with  the  deep  branch  of  the  princeps  cervicis  from 
the  occipital. 

Describe  the  axillary  artery. 

It  extends  from  the  lower  border  of  the  first  rib  to  the  lower 
border  of  the  tendon  of  the  teres  major  muscle,  where  it  takes 
the  name  of  the  brachial ;  it  is  divided  into  three  parts  by  the 
crossing  made  by  the  pectoralis  minor  muscle. 

Relations  of  the  first  portion :  anterior^  skin,  two  layers  of 
fascia,  platysma,  pectoralis  major,  costo-coracoid  membrane, 
external  anterior  thoracic  nerve,  acromio-thoracic  and  cephalic 
veins  ;  external,  brachial  plexus  ;  internal^  axillary  vein  ;  pos- 
terior^ fir.st  intercostal  space,  and  intercostal  muscle,  second 
and  part  of  third  serrations  of  the  serratus  magnus,  posterior 
thoracic,  and  internal  anterior  thoracic  nerves. 

Second  portion :  in  front.,  integument,  fasciae,  pectoralis 
major  and  minor ;  external^  outer  cord  of  the  brachial  plexus ; 
internal,  axillary  vein,  inner  cord  of  the  plexus ;  behind,  sub- 
scapularis,  posterior  cord. 

Third  portion :  anterior,  integument,  fasciae,  pectoralis 
major,  inner  head  of  the  median  nerve,  outer  brachial  vena 
comes ;  posterior,  subscapularis,  tendons  of  the  latissimus 
dorsi  and  teres  major,  musculo-spiral  and  circumflex  nerves; 
external,  coraco-brachialis,  median  and  musculo-cutaneous 
nerves ;  internal,  ulnar,  internal  cutaneous,  and  lesser  inter- 
nal  cutaneous  nerves,  axillary  vein. 

The  frst  portion  is  2.5  cm.  (1  inch)  long,  and  gives  off  the 
superior  thoracic  branch  ;  the  second  portion  is  3  cm.  (1-1-  inch) 
long,  and  gives  off  the  acromio-thoracic  and  long  thoracic  ;  the 
third  portion  is  7.5  cm.  {?>  inches)  long,  and  gives  oft"  the  alar 
thoracic,  subscapular,  posterior  circumflex,  anterior  circumflex, 
and  often  the  accessory  external  mammary. 

The  branches  are  : 

Superior  thoracic,  supplying  the  pectoral  muscles  and  the 
thoracic  wall. 

Acromio-thoracic,  supplying  the  deltoid  by  acromial  branches, 
the  serratus  magnus  and  pcctorales  by  the  thoracic,  the  descend- 
ing, or  humeral,  which  runs  with  the  cephalic  vein  between  the 


198  ESSENTIALS  OF  HUMAN   ANATOMY. 

deltoid  and  the  pectoralis  major,  and  the  clavicular  to  the  sub- 
clavius  muscle. 

Long  thoracic  (external  mammary),  to  the  chest-muscles  and 
mammary  gland. 

Alar  thoracic,  supplies  the  axillary  glands. 

Subscapular,  anastomosing  with  the  supra  and  posterior 
scapular  arteries,  and  giving  oft'  the  dorsalis  scapulst  branch. 

Posterior  circmn.flf'x,  to  the  deltoid  muscle  and  shoulder-joint ; 
it  anastomoses  with  the  anterior  circumflex,  suprascapular, 
acromio-thoracic,  and  superior  profunda  arteries. 

Anterior  circumjlex,  to  the  shoulder-joint  and  deltoid. 

Accessory  external  mammary ,  often  is  a  branch  from  the  third 
portion,  runs  downward  and  inward,  and  supplies  the  skin  and 
fascia  on  the  side  of  the  thorax. 

Describe  the  brachial  artery. 

A  continuation  of  the  axillary,  extending  from  the  lower 
border  of  the  teres  major  tendon  to  its  bifurcation  into  the 
radial  and  ulnar,  usually  opposite  the  neck  of  the  radius ;  the 
median  nerve  crosses  it  from  without  inward  about  midway  in 
its  course. 

Its  relations  are :  in  front,  integument,  fasciae,  bicipital 
fascia,  median  basilic  vein,  and  median  nerve ;  externally, 
vena  comes,  median  nerve  (above),  coraco-brachialis,  and  bi- 
ceps ;  internally,  vena  comes,  internal  cutaneous  and  ulnar 
nerves,  median  nerve  (below),  basilic  vein;  behind,  middle  and 
inner  heads  of  the  triceps,  musculo-spiral  nerve,  superior 
profunda  artery,  insertion  of  the  coraco-brachialis,  brachi- 
alis  anticus.  Its  branches  enumerated  from  above  down- 
ward are  : 

Superior  profunda,  descending  with  the  musculo-spiral  nerve, 
giving  off"  a  posterior  articular  branch,  which  anastomoses  with 
the  interosseous  recurrent  and  anastomotica  magna,  while  the 
anterior  terminal  twigs  of  the  main  trunk  inosculate  with  the 
radial  recurrent. 

Medullary  artery,  to  the  humerus. 

Inferior  profunda,  anastomosing  with  the  posterior  ulnar  re- 
current and  anastomotica  magna. 

Anastomotica  magna,  anastomosing  with  the  posterior  artic- 
ular of  the  superior  profunda,  inferior  profunda,  and  posterior 
ulnar  recurrent. 


THE   ARTERIES.  199 

Muscular,  to  the  arm -muscles  ;  special  ones  to  the  biceps  and 
deltoid. 

Describe  the  radial  artery. 

It  appears  to  be  a  continuation  of  the  brachial,  but  is  much 
smaller,  extending  from  the  bifurcation  at  the  elbow  along  the 
radial  side  of  the  forearm  to  the  wrist,  where,  winding  around 
the  thumb,  it  passes  between  the  two  heads  of  the  first  dorsal 
interosseous  muscle  to  the  palm,  there  inosculating  with  the 
deep  or  communicating  branch  of  the  ulnar  to  form  the  deep 
palmar  arch. 

Its  relations  are  :  in  front,  skin,  fasciae,  supinator  longus  mus- 
cle ;  internally,  pronator  teres  and  flexor  carpi  radialis  ;  exter- 
nally, supinator  longus,  radial  nerve  ;  behind,  tendon  of  the 
biceps,  supinator  brevis,  flexor  sublimis  digitorum,  pronator 
teres,  flexor  longus  pollicis,  pronator  quadratus,  radius. 

The  branches  of  the  radial  are  in  the 

Forearm  Wrist 

Radial  recurrent.  Posterior  carpal, 

Muscular,  First  dorsal  interosseous, 

Superficialis  volae,  Dorsales  pollicis, 

Anterior  carpal.  Dorsalis  indicis. 

Hand 
Princeps  pollicis, 
Radialis  indicis. 
Three  superior  perforating, 
Three  palmar  interosseous. 
Palmar  recurrent. 

The  last  three  are  branches  from  the  deep  palmar  arch. 

Describe  the  ulnar  artery. 

J^arger  than  the  i)receding,  it  passes  from  the  bifurcation 
obliquely  inward  to  the  middle  of  the  forearm,  thence  runs 
along  its  ulnar  border,  across  the  annular  ligament  to  the  radial 
side  of  the  pisiform  })one,  curving  across  the  palm,  where,  either 
anastomosing  with  the  superficialis  volae,  princeps  pollicis,  or 
radialis  indicis  of  the  radial,  it  forms  the 

SuiH'rJicial  p<dniar  arcli,  whose  branches  are  the  four  digitals. 

Relations :    in  front,  fascia),  superficial   layer  of  the  flexor 


200 


ESSENTIALS   OF   HUMAN   ANATOiMY. 


muscles,  median  nerve  ;   internalhj,  flexor  carpi  ulnaris,  ulnar 
nerve  ;  exienudhj,  flexor  sublimis  digitorum  ;   behliul^  brachialis 
anticus.  flexor  profundus  digitorum. 
The  branches  of  the  ulnar  are  in  the 


Forearm 

Anterior  ulnar  recurrent, 
Posterior  ulnar  recurrent, 

_,  .  (  Anterior  interosseous 

Common  interosseous 

Muscular. 


I  Posterior  interosseous 


Median, 

Muscular, 

Medullary  to 
the  radius, 

Medullary  to 
the  ulna, 

Anterior  com- 
municating, 

Terminal. 


Wrist 
Anterior  carpal. 
Posterior  carpal. 

Hand 
Deep,  or  communicating  branch. 
Superficial  palmar  arch — four  digitals. 

Describe  the  thoracic  aorta. 

Commencing  at  the  left  side  of  the  lower  border  of  the 
fourth  thoracic  vertebra,  it  terminates  at  the  aortic  opening,  in 
the  diaphragm  in  front  of  the  body  of  the  last  thoracic  ver- 
tebra. 

RrJdfions :  in  front ^  left  pulmonary  artery,  left  bronchus, 
pericardium,  esophagus  (below)  ;  right  side,  esophagus,  vena 
azygos  major,  thoracic  duct ;  left  side,  left  pleura  and  lung, 
esophagus  (below)  ;  hehind,  vertebral  column,  vena  azygos 
minor. 

Its  branches  are  visceral  and  parietal. 

Peric(irdi(d.  variable  in  number  and  origin,  for  the  pericar- 
dium. 

BroncJu'rd.  variable  in  number  and  origin,  usually  one  right 
and  two  left,  for  the  lung-tissue  proper. 

Esophageal,  commonly  numbering  four  to  five,  anastomosing 
around  the  esophagus  with  branches  of  the  inferior  thyroid, 
phrenic,  and  gastric  arteries. 


THE   ARTERIES.  201 

Posterior  mediastinal^  numerous  and  small  to  the  glands, 
areolar  tissue,  and  vertebral  portion  of  the  diaphragm. 

Infercosfais,  usually  nine  on  either  side,  each  dividing  into 
an  anterior  and  a  posterior  branch,  the  former  subdividing  into 
two  at  the  angle  of  the  rib,  one  branch  running  in  the  groove 
at  the  lower  border  of  the  rib  above,  the  other  running  along 
the  upper  border  of  the  rib  below,  in  front  both  anastomosing 
with  the  anterior  intercostal  branches  of  the  internal  mammary, 
with  the  thoracic  branches  of  the  axillary,  with  the  epigastric, 
phrenic,  and  lumbar  arteries  ;  the  posterior  division  supplies 
the  vertebrae,  spinal  cord,  dorsal  muscles,  and  skin. 

Subcostal  J  or  the  ticdfth  thoracic  artery^  passes  along  the 
lower  border  of  the  twelfth  rib. 

Describe  the  abdominal  aorta. 

It  commences  at  the  aortic  opening  of  the  diaphragm  in 
front  of  the  body  of  the  last  thoracic  vertebra,  whence  descend- 
ing a  little  to  the  left  of  the  vertebral  column  it  terminates  on 
the  body  of  the  fourth  lumbar  vertebra  by  dividing  into  the 
common  iliacs. 

Relations :  anterior^  lesser  omentum  and  stomach.  Spigelian 
lobe  of  the  liver,  lower  end  of  the  esophagus,  celiac  axis  and 
branches,  inferior  mesenteric,  spermatic  or  ovarian  arteries^ 
splenic  vein  and  commencement  of  the  vena  portse.^  left  renal  vein, 
aortic  and  soljtr  plexuses,  j^ancreas,  2'>'>'^f^^^f't'c  diiodemmi,  small 
intestines,  mesentery,  transverse  mesocolon,  lymphatic  glands  and 
vessels  ;  of  the  above  the  parts  in  it(dics  are  in  contact  with  the 
aorta;  posterior,  left  lumbar  veins,  left  crus  of  the  diaphragm, 
beginning  of  the  thoracic  duct,  vertebral  column  ;  right  side, 
right  crus  of  the  diaphragm,  inferior  vena  cava,  vena  azygos 
major,  thoracic  duct,  right  semilunar  ganglion,  right  great 
splanchnic  nerve,  Spig(!lian  lobe  of  the  liver  ;  left  side,  loft  crus 
of  the  diaphragm,  left  great  splanchnic  nerve,  left  semilunar 
ganglion,  tail  of  the  pancreas. 

Its  branches  are : 

Celiac  axis,  arises  opposite  the  margin  of  the  diaphragm, 
passes  for  half  an  inch   forward  to  divide  into  the 

(iastrie  or  coronary,  passing  upward  to  the  left  to  the  cardia  ; 
it  turns  sharply  froT)i  the  left  to  the  right  along  the;  lesser  cur- 
vature c»f  the  stomach,  anastomosing  with  the  aortic  esophageal, 
splenic,  and  hepatic  arteries. 


202  ESSENTIALS  OF  HUMAN   ANATOMY. 

Hepatic,  dividing  in  the  transverse  fissure  into  the  right 
and  left  terminal  branches  for  the  same  lobes  of  the  liver ; 
its  branches  are — 

Pancreatic, 

Pyloric, 

/-,     ,       1      T       1.        (  Gastro-epiploica  dextra, 
(jrastro-duodenalis     <  ^  .•       i      i       i- 

(  rancreatico-duodenaiis  superior, 

Cystic, 

whereby  it  supplies  the  parts  indicated  by  the  names,  and 
anastomoses  with  the  splenic,  gastric,  and  superior  mesenteric 
arteries. 

Splenic,  the  largest  branch,  passes  behind  the  upper  border 
of  the  pancreas  to  the  spleen,  giving  oiF  five  or  six  splenic 
branches,  and  the 

Pancreaticae  parvae,        Gastric  (vasa  brevia), 
Pancreatica  magna,         Gastro-epiploica  sinistra. 

Inferior  phrenic,  one  on  each  side  (sometimes  one  from  the 
celiac  axis  instead  of  the  aorta,  or  by  a  common  trunk)  to  the 
under  surface  of  the  diaphragm.  Each  gives  off  a  superior 
suprarenal  artery. 

Superior  mesenteric  comes  off  about  one-quarter  inch  below 
the  celiac  axis,  arching  forward  and  downward  to  the  left,  sup- 
plying all  of  the  small  intestine,  except  the  first  part  of  the 
duodenum,  also  the  cecum,  ascending,  and  transverse  colon, 
giving  off  the 

Inferior  pancreatico-duodenal,  Ileo-colic, 

Vasa  intestini  tenuis,  Colica  dextra, 

Colica  media. 

Inferior  mesenteric,  arising  from  the  left  side  of  the  aorta 
two  inches  above  the  bifurcation,  passes  down  into  the  left 
iliac  fossa  and  pelvis,  supplying  the  descending  colon,  sigmoid 
flexure,  and  greater  part  of  the  rectum,  anastomosing  above 
with  the  middle  colic  of  the  superior  mesenteric,  supplying  the 
transverse  colon  in  part ;  its  branches  are  : 

Colica  sinistra,       Sigmoid,       Superior  hemorrhoidal. 

Middle  supraroial,  each  arises  opposite  the  superior  mesen- 
teric to  supply  the  suprarenal  body. 

Renal,  spring  nearly  at  right  angles  from  the  sides  of  the 


THE   ARTERIES.  203 

aorta  below  the  superior  mesenteric,  the  right  longer  and  lower 
than  the  left ;  each  divides  into  four  or  five  branches  before 
entering  the  hilum,  intervening  between  the  renal  vein  in  front 
and  the  ureter  behind  and  below.  It  gives  off  the  inferior 
suprarenal  artery^  making  three  for  that  body. 

Spermatic  (ovarian  in  the  female),  spring  from  the  front  of 
the  aorta  on  each  side,  a  little  below  the  renals,  run  behind  the 
peritoneum  to  pass  in  the  male  through  the  abdominal  ring  to  the 
testis,  in  tha  female  between  the  laminae  of  the  broad  ligament 
to  the  ovary,  Fallopian  tube,  uterus,  and  to  the  round  ligament 
and  inguinal  canal. 

Lumbar.,  commonly  four  on  each  side  corresponding  to  the 
intercostals,  and  like  them  dividing  into  : 

Dorsal  branches  to  the  vertebrae,  spinal  cord,  and  back  mus- 
cles, and  abdominal  branches,  passing  forward  to  anastomose 
with  twigs  from  the  epigastric,  internal  mammary,  intercostals, 
ilio-lumbar,  and  circumflex  iliac. 

Middle  sacral.)  springs  from  the  bifurcation  of  the  aorta, 
descends  along  the  middle  of  the  sacrum  and  coccyx,  sending 
branches  to  the  rectum,  anastomosing  with  the  hemorrhoidal 
and  lateral  sacral  arteries,  terminating  in  the  coccygeal  gland. 

Describe  the  common  iliac  arteries. 

They  extend  from  the  aortic  bifurcation  at  the  left  of  the 
umbilicus,  corresponding  to  a  line  touching  the  highest  points 
of  the  iliac  crests,  to  divide  opposite  the  intervertebral  disk 
between  the  last  lumbar  vertebra  and  the  sacrum,  into  the  in- 
ternal and  the  external  iliac  ;  the  right  vessel  is  somewhat  the 
longer,  both  being  about  two  inches  long,  and  each  at  its  bifur- 
cation is  crossed  by  the  ureter. 

Relations  of  the  right  common  iliac:  in  front ^  peritoneum, 
small  intestine,  sympathetic  nerves,  ureter;  outer  side,  vena 
cava,  right  common  iliac  vein,  psoas  muscle  ;  behind,  two  last 
lumbar  vertebra3,  right  and  left  common  iliac  veins. 

Reldfions  (f  the  left  common  iliac  :  in  front,  same  as  for  the 
right,  with  the  superior  hemorrhoidal  artery  added  ;  inner  side, 
left  common  iliac  vein  ;  outer  side,  psoas  muscle  ;  behind,  two 
last  lumbar  vertebrae,  left  common  iliac  vein. 

Describe  the  internal  iliac  artery. 

It  measures  about  one  and  a  half  inches,  arising  at  the  point 


204  ESSENTIALS  OF  HUMAN   ANATOMY. 

of  bifurcation  of  the  common  iliac,  to  divide  at  the  upper 
mari^in  of  the  great  sacro-sciatic  foramen  into  the  anterior  and 
the  posterior  trun/:.  In  the  adult  it  is  smaller  than  the  exter- 
nal, the  reverse  in  the  fetus.  A  partially  obliterated  cord,  the 
fetal  hypogastric  artery^  extends  from  its  bifurcation  to  the 
bladder. 

Relations:  in  front,  peritoneum,  ureter;  outer  side,  psoas 
magnus ;  inner  side,  internal  iliac  vein,  peritoneum;  behind, 
external  iliac  vein  (above),  internal  iliac  vein,  lumbo-sacral 
nerve,  sacrum. 

Branches  of  the  anterior  division  :  Superior  vesical,  part  of 
the  fetal  hypogastric  artery- ;  it  gives  off  the  artery  of  the  vas 
deferens  and  supplies  the  ureter,  as  well  as  the  bladder. 

Middle  vesical,  usually  a  branch  of  the  former  to  the  bladder 
and  vesiculae  seminales. 

Inferior  vesical  (vaginal  in  the  female),  arising  in  common 
with  the  middle  hemorrhoidal,  is  distributed  to  the  base  of  the 
bladder,  prostate  gland,  and  seminal  vesicles. 

Middle  hemorrhoidal,  supplies  the  rectum. 

Uterine,  anastomoses  with  the  ovarian ;  gives  twigs  to  the 
bladder  and  ureter. 

Ohturator,  passes  through  the  obturator  canal  to  the  thigh, 
there  dividing  into  an  internal  and  an  external  branch,  anasto- 
mosing with  twigs  of  the  internal  circumflex  ;  inside  the  pelvis 
its  branches  are  : 

Iliac,  to  the  same  named  bone  and  muscle  anastomosing  with 
the  ilio-lumbar  ;  a  vesiad,  to  the  bladder  ;  and  a  pubic,  inosculat- 
ing back  of  the  pubes  with  the  epigastric  and  its  fellow  ;  in 
two  out  of  three  cases  the  obturator  springs  from  the  internal 
iliac,  in  one  in  three  and  a  half  cases  from  the  epigastric, 
in  one  in  seventy-two  cases  it  has  two  roots. 

Internal pudic.  the  smaller  terminal  of  the  anterior  division, 
is  distributed  to  the  external  organs  of  generation ;  giving  off 
the  following  branches : 

Inferior  hemorrhoidal,  Muscular, 

Superficial  perineal.  Artery  of  the  bulb, 

Transverse  perineal.  Artery  of  the  corpus  cavernosum, 

Dorsal  artery  of  the  penis. 

tSciatic,  the  larger  terminal,  supplies  the  muscles  on  the  back 
of  the  pelvis  ;  its  branches  are  : 


THE   ARTERIES.  205 

Muscular,  Coccygeal,  Comes  nervi  ischiadici, 

Inferior  gluteal,  Anastomotic,  Cutaneous, 

Articular  (hip). 

Branches  of  the  posterior  division  :  Ilio-lumhar^  dividing  into 
an  iliac  and  a  lumbar  branch  supplying  the  muscular,  spinal, 
and  nutrient  branches,  anastomosing  with  the  last  lumbar, 
external  circumflex,  gluteal,  epigastrics,  deep  circumflex  iliac, 
and  obturator. 

Lateral  sacral^  superior  and  inferior  on  each  side  emerge 
from  the  posterior  sacral  foramina,  anastomosing  with  the  glu- 
teal and  sciatic  arteries. 

Gluteal  ends  the  posterior  division,  divides  into  a  superficial 
and  a  deep  branch,  the  latter  giving  off"  a  superior  and  an  in- 
ferior branch. 

It  has  muscular,  cutaneous,  nutrient  (to  the  ilium),  and  artic- 
idar  branches,  anastomosing  with  the  circumflex  iliac,  external 
circumflex,  and  sciatic  arteries. 

Describe  the  external  iliac  artery. 

Passes  along  the  inner  border  of  the  psoas  muscle  from  the 
bifurcation  of  the  common  iliac  to  Pouparts  ligament ;  a  line 
drawn  from  the  left  side  of  the  umbilicus  to  the  midpoint 
between  the  symphysis  pubis  and  the  anterior  superior  iliac 
spine  (in  female's  a  little  nearer  the  former),  indicates  the 
course  of  the  common  and  external  iliac. 

Rdations :  in  front,  peritoneum,  intestines,  and  fascia, 
lymphatic  vessels  and  glands;  near  Pouparts  ligament  arc  the 
spermatic  vessels,  genital  branch  of  the  genito-crural  nerve, 
deep  circumflex  iliac  vein  ;  externalli/,  psoas  magnus,  iliac 
fascia  ;  internally,  external  iliac  vein  and  vas  deferens  ;  behind, 
external  iliac  vein,  psoas  magnus,  iliac  fascia. 

Its  branches  are : 

Muscular,  Lymphatic  (to  glands). 

Deep  epigastric.  Deep  circumflex  iliac. 

Deep  epigastric,  usually  coming  off"  just  above  Poupart's 
ligament,  passing  between  the  peritoneum  and  transversalis 
fascia,  pierces  the  fascia  and  enters  the  sheath  of  the  rectus 
muscle  under  the  semilunar  fold  of  Douglas;  it  anastomoses 


206  ESSENTIALS  OF  HUMAN   ANATOMY. 

with  the  internal  mammary  and  inferior  intercostal  arteries ; 
its  branches  are  : 

Cremasteric,         Pubic,         Muscular,         Superficial. 

Deep  circumflex  iliac,  arises  externally  nearly  opposite  the 
epigastric,  running  along  the  inner  side  of  the  iliac  crest,  there 
to  pierce  the  transversalis  and  anastomose  with  the  ilio-lumbar 
and  gluteal  arteries.  An  ascending  branch  joins  the  lumbar 
and  epigastric  arteries. 

Describe  the  femoral  artery  (Fig.  105). 

Extending  from  Poupart's  ligament,  where  the  letters  N.  A. 
V.  indicate  its  relation  with  the  anterior  crural  nerve  and 
femoral  vein,  it  terminates  at  the  opening  in  the  adductor 
magnus  (the  end  of  Hunter's  canal)  ;  the  upper  two-thirds  of 
a  line  drawn  from  the  midpoint  between  the  anterior  superior 
iliac  spine  and  symphysis  pubis  to  the  inner  side  of  the  internal 
condyle  of  the  femur  indicates  its  course.  The  artery  and 
vein  are  enclosed  in  a  strong  fibrous  sheath,  but  separated  by  a 
partition  from  each  other,  and  lie  very  superficially  above,  in 
Scarpa's  triangle,  bisecting  it. 

The  femoral  artery  has  three  parts  :  common  femoral  is  one 
to  two  inches  long,  dividing  into  the  superficial  and  the  deep 
femoral  (^profunda  femoris). 

What  is  Scarpa's  triangle  ? 

It  is  a  space  bounded  above  by  Poupart's  ligament,  inter- 
nally by  the  outer  edge  of  the  adductor  longus,  externally  by 
the  inner  edge  of  the  sartorius,  the  floor  being  formed  by  the 
iliac,  psoas,  pectineus,  and  part  of  the  adductor  brevis  muscles. 

Relations  of  the  common  femoral  artery :  anterior,  skin,  super- 
ficial fascia,  superficial  inguinal  glands,  iliac  portion  of  the 
fascia  lata,  anterior  part  of  the  femoral  sheath  from  the 
transversalis  fascia,  crural  branch  of  the  genito-crural  nerve, 
superficial  circumflex  iliac  and  superficial  epigastric  veins ; 
posterior,  posterior  part  of  the  femoral  sheath  from  the  iliac 
fascia,  pubic  portion  of  the  fascia  lata,  nerve  to  the  pectineus, 
psoas  muscle  and  tendon,  pectineus,  capsule  of  the  hip-joint ; 
internal,  femoral  vein ;  external,  anterior  crural  nerve  and 
psoas  muscle. 

Relations  of  the  superficial  femoral  artery  in  Scarpa's  tri- 


THE  AKTEKIES. 


207 


l<m^^ 


'mdi 


# 


y/j*p 


Fig.  105.— The  femoral  artery  and  the  side-       Fig.  106.— The  anterior  tibial  and 
view  of  the  popliteal  artery.        (Leidy.)    the  dorsalis  pedis  arteries. 


208  ESSENTIALS  OF  HUMAN    ANATOMY. 

angle  and  Hnntcrs  canal:  antcrwr^  skin,  superficial  and  deep 
fasciae,  internal  cutaneous  and  saphenous  nerves,  sartorius. 
aponeurotic  covering  of  Hunter's  canal ;  po^fcrior.  femoral 
vein,  profunda  artery  and  vein,  pectineus,  adductor  longus  and 
magnus  muscles ;  external.,  long  saphenous  nerve,  nerves  to 
the  vastus  internus,  vastus  internus  muscle,  and  femoral  vein  ; 
internal^  adductor  longus,  magnus,  and  sartorius  liiuscles. 

The  femoral  artery  gives  off  the  following  branches : 

Snperficial  epigastric*^ ^  to  the  inguinal  glands,  fascia,  and  skin, 
anastomosing  with  the  superficial  branches  of  the  deep  epi- 
gastric. 

Snperficial  circumjiex  iliac^^  to  the  skin  of  the  groin,  glands 
etc.,  anastomosing  with  the  deep  circumflex,  iliac,  gluteal,  and 
external  circumflex  arteries. 

Superior  external  pudic^,  to  the  skin  of  the  genitals,  anasto- 
mosing with  the  terminal  branches  of  the  internal  pudic,  its 
fellow,  the  inferior  pudic,  and  the  cremasteric  arteries. 

Inferior  external p)vdic^,  to  the  skin  of  the  genitals  and  peri- 
neum, anastomosing  with  the  superficial  perineal  and  superior 
external  pudic  arteries. 

Muscular  ",  to  the  sartorius  and  vastus  internus. 

Anastomotica  magna^'\  arises  just  above  Hunter's  canal,  and 
divides  into  a  superficial  (cutaneous)  and  a  deep  branch, 
anastomosing  with  the  internal  and  superior  external  articu- 
lar, and  the  anterior  tibial  recurrent  arteries'*. 

Profunda  femoris"^ ^  springing  from  the  oi  ter  back  part  of 
the  femoral  from  one  to  two  inches  below  Poupart's  ligament, 
terminating  at  the  lower  third  of  the  thigh  by  the  small  fourth 
perforating  artery  ;  it  gives  off: 

External^  and  Internal  Circumflex^     Four  perforating'". 

Describe  the  popliteal  artery. 

It  commences  at  the  opening  in  the  adductor  magnus,  and 
passing  obliquely  downward  and  outward  behind  the  knee- 
joint,  divides  opposite  the  lower  border  of  the  popliteus  mus- 
cle into  the  anterior  and  the  po.s^mo?-  tibial  arteries. 

Relations  :  in  the  upper  part  of  the  popliteal  space,  the  three 
chief  structures  are  arranged  from  behind  forward  and  without 
inward  in  a  certain  order ;  first  comes  the  internal  popliteal 
nerve,  next  the  popliteal  vein,  deepest  and  most  internal  the 
popliteal  artery  ;  anterior^  are  the  femur,  posterior  ligaments 


THE  ARTERIES.  •  Wd 

of  the  knee-joint,  a  bit  of  the  head  of  the  tibia,  popliteal 
fascia,  and  muscle  ;  posterior,  skin,  fasciae,  semimembranosus, 
popliteal  vein,  internal  popliteal  nerve,  sometimes  a  twig  from 
the  obturator  nerve,  inner  head  of  the  gastrocnemius,  plantaris, 
arch  of  the  soleus  ;  internal,  semimembranosus,  adductor  mag- 
nus  tendon,  internal  condyle,  inner  head  of  the  gastrocnemius, 
internal  popliteal  nerve  (below),  popliteal  vein  (below);  exter- 
nal, biceps,  outer  condyle,  outer  head  of  the  gastrocnemius, 
plantaris,  internal  popliteal  nerve  (above),  popliteal  vein 
(above).     Its  branches  are  : 

Superior  muscular,  Superior  external  articular, 

Inferior  muscular  or  sural,  Superior  internal  articular. 

Cutaneous,  Inferior  internal  articular, 

Azygos  articular.  Inferior  external  articular. 

These  anastomose  with  the  perforating  terminal  branch  of 
the  profunda,  descending  branch  of  the  external  circumflex, 
anastomotica  magna,  anterior  tibial  recurrent,  and  with  each 
other,  except  the  muscular;  the  azygos  articular  enters  the 
back  of  the  joint  to  supply  the  synovial  membrane  and  inter- 
articular  ligaments. 

Describe  the  anterior  tibial  artery  (Fig.  106). 

Commencing  at  the  lower  border  of  the  popliteus  muscle,  pass- 
ing between  the  two  heads  of  the  tibialis  posticus  by  the  defect 
at  the  upper  part  of  the  interosseous  membrane,  lying  upon  its 
anterior  surface  and  that  of  the  lower  third  of  the  tibia,  it  ter- 
minates at  the  front  of  the  bend  of  the  ankle  in  the  dornaHs 
pedis  artery  ;  the  anterior  tibial  nerve  lies  externally  ;  branches 
are  the  posterior  and  anterior  tibial  recurrent,  superior  Jibular, 
muscular,  internal  and  external  malleolar ;  the  posterior  recur- 
rent and  superior  fibular  rise  from  the  artery  before  it  pierces 
the  membrane. 

liclations:  in  front,  skin,  fasciae,  anterior  tibial  nerve, 
tibialis  anticus,  extensor  longus  digitorum,  extensor  longus 
hallucis,  anterior  annular  ligament;  internally,  tibialis  anticus, 
extensor  longus  hallucis;  r'x^^r//^/////,  anterior  tibial  nerve,  ex- 
tensor longus  digitorum,  extensor  longus  hallucis;  behind, 
interosseous  membrane,  tibia,  anterior  ligament  of  the  ankle- 
joint. 

14 


210  ESSENTIALS   OF   HUMAN    ANATOMY. 

Describe  the  dorsalis  pedis  artery  ^ 

It  extends  from  the  front  of  the  bend  of  the  ankle  to  the 
back  part  of  the  first  intermetatarsal  space,  where  it  divides 
into  the  first  dorsal  tiifei-osseous^  (dorsalis  hallucis),  supply- 
ing both  sides  of  the  great  toe  and  adjoining  side  of  the  second; 
the  plantar  digital  branch  (communicating),  dipping  down 
between  the  heads  of  the  first  dorsal  interosseous  muscle  to 
reach  the  sole  of  the  foot,  and  form  with  the  external  plantar  the 
plantar  arch  ;  it  gives  oil"  tico  digit(d  branches^  one  for  the  inner 
side  of  the  great  toe  and  one  which  divides  for  the  contiguous 
sides  of  the  great  and  second  toes ;  the  other  branches  are  the 

Tarsal,  arching  outward  across  the  tarsus. 

Metatarsal^,  runs  anterior  to  the  preceding  over  the  bases  of 
the  metacarpal  bones,  giving  ofi"  the  second,  third,  and  fourth 
dorsal  interosseous,  from  which  arise  seven  dorsal  digitals  for 
the  outer  three  and  a  half  toes.  This  artery  lies  upon  the 
astragalus,  navicular,  and  middle  cuneiform  bones,  and  is  crossed 
by  the  innermost  tendon  of  the  extensor  brevis  digitorum. 

Describe  the  posterior  tibial  artery. 

It  extends  as  a  large  vessel  obliquely  downward  from  the 
lower  border  of  the  popliteus  muscle  along  the  tibial  side  of 
the  leg  to  the  midpoint  of  the  depression  between  the  inner 
ankle  and  heel,  where,  beneath  the  abductor  hallucis  muscle,  it 
divides  into  the  internal  and  the  external  plantar  ;  the  posterior 
tibial  nerve  lies  first  to  its  inner  side,  but  soon  crosses  it,  to 
remain  close  to  the  outer  side  ;  it  gives  off  the 

Perone(tl,  along  the  back  of  the  fibular  side  of  the  leg, 
brandies  of  which  are  muscular,  medidlary  to  the  fibula,  com- 
municating,  anterior  peroneal,  posterior  p)Groneal,  and  external 
calcaneal.  The  anterior  peroneal  anastomoses  with  the  exter- 
nal malleolar,  tarsal,  and  posterior  peroneal  arteries.  The  pero- 
neal artery  is  enveloped  by  the  flexor  longus  hallucis  muscle. 

The  posterior  tibial  also  gives  off"  muscular  branches,  medid- 
lary  to  the  tibia,  cutaneous,  communicating,  and  internal  malle- 
olar;  internal  calcane(d  u^ViSiWy  covciQ  ^vom.  the  external  plantar. 

Communicating,  to  the  peroneal,  passing  transversely  across 
the  back  of  the  tibia  about  two  inches  above  the  ankle. 

Relations :  in  front,  tibialis  posticus,  flexor  longus  digi- 
torum, tibia,  ankle-joint;  internally/,  posterior  tibial  nerve 
(upper  third)  ;  externally,  posterior  tibial   nerve  (lower  two- 


THE   ARTERIES.  211 

thirds)  ;  behind,  skin,  fasciae,  gastrocnemius,  soleus,  deep  trans- 
verse fascia,  posterior  tibial  nerve. 

Describe  the  internal  plantar  artery. 

The  smaller  terminal  of  the  posterior  tibial  runs  along  the 
inner  side  of  the  foot  and  great  toe,  giving  off  muscular,  cuta- 
neous, and  articular  branches. 

Describe  the  external  plantar  artery. 

It  passes  obliquely  outward  and  forward  to  the  base  of  the 
fifth  metatarsal,  whence  it  curves  inward  to  the  interval  be- 
tween the  bases  of  the  first  and  second  metatarsal  bones,  there 
anastomosing  with  the  plantar  digital  branch  of  the  dorsalis 
pedis,  completing  the  plantar  arch  ;  the  branches  given  off  in 
its  course  to  the  fifth  metatarsal  bone  are  the  internal  calcaneal, 
muscular,  and  cutaneous. 

Internal  calcaneal,  several  large  branches  to  the  inner  mus- 
cles of  the  sole,  fat  and  skin  of  the  heel,  anastomosing  with  the 
peroneal,  internal  malleolar,  and  external  calcaneal. 

The  branches  of  the  plantar  arch  are  : 

Three  posterior  perforating,  passing  up  the  three  outer  inter- 
metatarsal  spaces  to  anastomose  with  the  interosseous  from 
the  metatarsal. 

Four  digitals,  by  division  supplying  both  sides  of  the  three 
outer  toes,  and  the  outer  side  of  the  second — both  sides  of  the 
great  and  the  inner  side  of  the  second  toe  being  supplied  by 
the  plantar  digital  branch  of  the  dorsalis  pedis. 

The  digitals  give  off  three  anterior  j^erf orating  arteries  near 
their  bifurcations  into  the  collateral  digitals. 

Surgical  Anatomy  of  the  Arteries. 

The  student  must  remember  that  while  all  the  anastomosing 
vessels  coming  off  above  and  below  the  site  of  ligature  enlarge, 
and  should,  therefore,  be  carefully  impressed  upon  the  mind 
whore  enumerated  in  the  preceding  pages,  yet  the  blood,  by 
dissection,  has  been  found  to  pass  chiefly  by  the  vessels  men- 
tioned under  each  caption. 

Describe  the  collateral  circulation  after  ligature  of  the  com- 
mon carotid. 
The    chi(!f  coniniunications    are   between   the   superior    and 
inferior  thyroids,  the  profunda  cervicis  of  the  subclavian,  and 


212  ESSENTIALS   OF   HUMAN   ANATOMY. 

princeps  cervicis  of  the  occipital,  the  vertebral  taking  the  place 
of  the  internal  carotid  within  the  cranium. 

After  ligature  of  the  subclavian  (third  part). 

Between  the  suprascapular  and  the  posterior  scapular  with 
the  subscapular,  the  internal  mammary,  and  the  long  and  supe- 
rior thoracic  and  subscapular. 

After  ligature  of  the  axillary. 

If  below  the  acromio-thoracic,  chiefly  between  the  subscapular 
and  the  other  scapular  arteries  of  the  subclavian  and  long 
thoracic,  through  the  intercostals  with  the  internal  mammary  ; 
if  below  the  subscapular,  the  posterior  circumflex  anastomosing 
with  the  suprascapular  and  acromio-thoracic,  and-inosculations 
between  the  subscapular  and  the  superior  profunda. 

After  ligature  of  the  brachial. 

(1)  Upper  third,  by  anastomoses  between  the  circumflex  and 
subscapular  and  superior  profunda  ;  (2)  below  the  profunda 
arteries,  by  branches  of  the  profundae  anastomosing  with  the 
recurrents  of  the  ulnar,  radial,  and  interosseous  arteries. 

When  the  thoracic  aorta  is  obliterated. 

The  internal  mammary  anastomosing  with  the  intercostals ; 
phrenic  with  the  musculo-phrenic,  comes  nervi  phrenici  and 
deep  epigastric,  superior  intercostal  and  first  aortic  intercostal ; 
inferior  thyroid  with  the  first  aortic  intercostal ;  trans versalis 
colli  with  the  posterior  branches  of  the  intercostals  ;  axillary 
and  subclavian  branches  to  the  side  of  the  chest  with  the  lateral 
branches  of  the  intercostals. 

When  the  abdominal  aorta  is  tied. 

The  deep  epigastric  communicating  with  the  internal  mam- 
mary, the  intercommunications  of  the  superior  and  inferior 
mesenteric,  or  the  latter  with  the  internal  pudic,  and  the 
anastomoses  of  the  lumbar  with  the  branches  of  the  internal 
iliac. 

After  the  common  iliac  is  tied. 

The  anastomosis  of  hemorrhoidal  branches  of  the  internal 
iliac  with  the  superior  hemorrhoidal  from  the  inferior  mesen- 
teric, the  inosculations  of  the  uterine   and  ovarian,  and  of  the 


THE  VEINS.  213 

vesicalsof  opposite  sides,  that  of  the  lateral  sacral  with  the  middle 
sacral,  of  the  epigastric  with  the  internal  mammary,  intercostal 
and  lumbar,  of  the  ilio-lumbar  with  the  last  lumbar,  of  the 
obturators  with  one  another  and  the  deep  epigastrics,  of  the 
gluteal  with  the  lateral  sacral  branches. 

After  the  internal  iliac  is  tied. 

Same  as  above,  except  that  the  obturator  also  communicates 
with  the  internal  circumflex,  the  circumflex  and  perforating 
branches  of  the  profunda  with  the  sciatic,  and  the  circumflex 
iliac  with  the  ilio-lumbar  and  gluteal. 

After  the  external  iliac  is  tied. 

The  anastomoses  between  the  ilio-lumbar  and  the  circumflex 
iliac ;  the  gluteal  and  external  circumflex  ;  the  obturator  and 
internal  circumflex  ;  the  sciatic  with  the  superior  perforating 
and  the  two  circumflex  arteries  ;  the  internal  pudic  with  the 
external  pudic  and  internal  circumflex. 

After  the  common  femoral  is  tied. 

Anastomoses  of  gluteal  and  circumflex  iliac  with  the  exter- 
nal circumflex  ;  obturator  and  sciatic  with  internal  circumflex  ; 
ilio-lumbar  with  the  external  circumflex  ;  comes  nervi  ischiadici 
with  the  muscular  branches  of  the  popliteal. 

After  the  superficial  femoral  is  tied. 

Branches  from  the  profunda  anastomosing  with  the  superior 
and  inferior  articular  of  the  knee,  anastomotica  magna,  mus- 
cular, and  origins  of  the  anterior  and  posterior  tibial. 

(The  popliteal  is  never  tied  except  for  a  wound,  when  the 
articular  arteries,  anastomotica  magna,  recurrent  tibials,  per- 
forating and  muscular  branches  would  convey  the  blood.) 

The  Veins. 

Describe  the  veins. 

They  are  vessels  returning  venous  blood — /.  e.  blood  sur- 
charged with  carbonic  acid  gas — to  the  heart,  and  have  4^he 
same  coats  as  arteries,  but  not  so  thick,  especially  the  middle, 
in  consefjuence  collapsing  when  divided.  One  set  of  veins  only 
carries  other  than  venous  blood,  viz.  the  pulmonary  convey- 
ing arterial  blood  from  the  lungs  to  the  left  auricle.  Certain  of 
the  veins,  usually  the  superficial,  have  their  lining  membrane 


214  ESSENTIALS  OF  HUMAN   ANATOMY. 

forming  semilunar  redujilications  or  valves,  arranged  in  pairs 
opposite  one  another,  which  prevent  any  reflux  of  blood.  The 
large  arteries  are  accompanied  by  deep  veins  of  the  same 
name,  generally  included  in  the  same  sheath,  while  such  ves- 
sels as  the  brachial,  radial,  ulnar,  etc.  have  two  veins  each, 
called  vense  comites.  The  superficial  veins  run  between  the 
layers  of  the  superficial  fascia,  terminating  in  the  deep  veins, 
and  are  not  usually  accompanied  by  arteries.  All  veins  freely 
anastomose,  and  even  those  dignified  with  special  names  have 
very  irregular  origins  and  distributions. 

What  are  sinuses? 

A'enous  channels,  found  only  within  the  skull,  formed  by  a 
separation  of  the  layers  of  the  dura  mater,  and  lined  with 
endothelium  continuous  with  that  of  the  veins. 

How  are  the  veins  classed? 

As  belonging  to  the  pulmonary ,  systemic,  and  portal  systems, 
the  latter  an  appendage  of  the  systemic. 

Name  the  principal  veins  which  have  no  valves. 

The  venfe  cav93,  hepatic,  portal,  renal,  uterine,  ovarian, 
cerebral,  spinal,  and  pulmonary. 

Name  the  veins  of  the  head  and  neck. 

(1)  Frontal.  Facial,  Temporo-maxillary, 
Supraorbital,  Temporal,  Posterior  auricular. 
Angular,                Internal  Occipital. 

maxillary, 

(2)  Those  which  return  the  blood  from  the  head  and  face  : 
External  jugular,  Anterior  jugular, 
Posterior  external  jugu-  Internal  jugular, 

lar.  Vertebral. 

(3)  Veins  of  the  cranium  :  Sunerfie^'al   and 
Veins  of  the  diploe,         Cerebral  {  Deep,or  Venje  Galeni. 
i^ereDeiiar, 

Name  the  sinuses  of  the  dura  mater. 

Above  and  behind,  one  superior  and  one  inferior  longitudinal, 
straight,  two  lateral,  two  occipital;  at  the  base  are  two  cavernous, 
circular^  transverse,  two  snp>erior  and  two  inferior  petrosal. 

Eight  or  nine  emissary  veins  of  Santorini  aiford  communi- 


THE  VEINS. 


215 


cation  between  the  sinuses  of  the  dura  and  the  external  veins 
by  the  following  foramina  :  mastoid, parietal,  j^osterior  condylar, 
through  the  external  occipital  protuherance,  foramen  ovale, 
foramen  lacerum,  foramen  Vesalii,  carotid  canal,  anterior  con- 
dylar foramina. 

How  is  the  internal  jugular^  formed  (Fig.  107)? 

By  the  junction  of  the  lateral  and  inferior  petrosal  sinuses 
just  outside  the  jugular  foramen  ;  at  the  base  of  the  neck  the 
internal  jugular  unites  with  the  subclavian  vein  to  form  the 
innominate  vein — at  or  above  the  junction  is  a  pair  of  valves; 
into  the  jugular  empty  the  common  facial,  lingual,  pharyngeal, 
superior  and  middle  thyroid  veins. 

Where  do  the  following  veins  empty? 

The  external  jugular^,  into  the  subclavian  vein  external  to 
the  internal  jugular  ;  th.Q  posterior  external  jugular,  into  the  ex- 
ternal jugular  ;  the  anterior  Jngidar,  into  the  termination  of  the 
external  jugular  or  the  subclavian  vein  ;  the  vertebral  descends 
through  the  vertebral  foramina  in  the  transverse  processes  of 
the  cervical  vertebrae  to  empty  into  the  back  of  the  innominate 
vein,  valves  guarding  the  orifice. 

Describe  the  veins  of  the  upper  extremity. 

They  are  superficial  and  deep,  the  latter  being  the  vense 
comites  of  the  arteries  ;  commencing  as  digitals,  these  empty 
into  the  interosseous,  these  into  the  palmar  until  the  radial  and 
idnar  comites  are  formed,  which,  uniting,  form  the  brachial 
venae,  comites,  consisting  of  two  veins  with  transverse  anasto- 
moses. The  superficial  veins  running  in  the  superficial  fascia 
are  called  : 


Radial 

Median 

Anterior  and 
Posterior  ulnar 


Median  cephalic 
Median  has  ilia 


Cephalic 
Brachial 
Basilic 


Axillary 


Describe  the  axillary  vein. 

It  is  a  continuation  of  the  basilic,  receiving  the  brachial  and 
veins  of  corresponding  names  with  the  arteries  of  the  axilla, 
and  is  continued  beneath  the  clavicle  under  the  name  of  the 
suhclam'an  vein^ ;  it  has  valves  opposite  the  lower  border  of  the 


216 


ESSENTIALS  OF  HUMAN   ANATOMY. 


subscapular  muscle,  also  at  the  mouths  of  the  cephalic  and 
subscapular  veins. 

Describe  the  subclavian  vein**. 

It  extends  from  the  lower  border  of  the  first  rib  to  the  back 
of  the  sterno-clavicular  joint,  there  uniting  with  the  internal 
jugular  to  form  the  vena  innominata — the  subclavian  vein  lies 

in  front  of  the  artery  with  the  scalenus 
anticus  muscle  interposed  at  its  second 
part ;  its  tributaries  are  the  external  and 
the  anterior  jugular  and  a  tributary  of 
the  cephalic  ;  on  the  right  side  the  right 
lijmpliatic  duct  empties  at  the  junction 
of  the  subclavian^  and  internal  jugular 
veins,  and  at  the  same  point  on  the  left 
side  the  tlioracic  duct. 

How    are    the    venae     innominatse^-^ 
formed  ? 

Each  by  the  subclavian  and  internal 
jugular,  which  unite  just  below  the  first 
costal  cartilage  to  form  the  superior  vena 
cava*;  the  riglit  iimominate  is  about 
one  and  a  half  inches  long,  receiving 
blood  by  the  right  vertebral,  internal 
mammary,  inferior  thyroid,  often  the 
right  superior  intercostal  vein  ;  the  left 
vein  is  larger  and  about  two  and  one-half 
inches  long ;  the  left  vertebral,  internal 
mammary,  inferior  thyroid,  superior  in- 
tercostal, and  occasionally  some  thymic 
and  pericardiac  veins  empty  into  it. 

Describe  the  superior  vena  cava*. 

It  measures  from  two  and  a  half  to 
three  inches  and  is  formed  by  the  union 
of  the  two  innominate  veins ^'*''  is  half 
covered  by  the  pericardium  and  enters 
the  upper  part  of  the  right  auricle  ;  it  returns  the  blood  of 
the  upper  half  of  the  body  and  receives  the  vena  azygos  major 
and  small  mediastinal  and  pericardiac  veins. 


Fig.  107.— The  veiipe  cavse 
and  azygos  veins  (Leidy). 


THE  VEINS.  217 

Describe  the  azygos  veins. 

They  connect  the  superior  and  the  inferior  venae  cavae,  tak- 
ing the  place  of  those  vessels  in  that  part  of  the  chest  occupied 
by  the  heart. 

The  right  azygos^^  (vena  azygos  major)  commences  opposite 
the  first  and  second  lumbar  vertebrae  by  a  tributary  from  the 
right  lumbar  or  renal  vein,  or  from  the  inferior  vena  cava, 
enters  the  thorax  by  the  aortic  opening,  passes  to  the  level 
of  the  fifth  rib,  and  arches  over  the  root  of  the  right  lung  to 
empty  into  the  superior  cava,  receiving  in  its  course  the  nine 
or  ten  right  lower  intercostal  veins,  the  vena  azygos  minor, 
esophageal,  mediastinal,  and  right  bronchial  veins;  also  it  is 
usually   connected  with  the  right  superior  intercostal  vein. 

The  left  lower  azygos^^  (vena  azygos  minor)  commences  by  a 
tributary  from  the  left  lumbar  or  renal  vein,  enters  the  thorax 
through  the  left  crus  of  the  diaphragm,  passes  across  from  the 
left  side  of  the  vertebral  column  at  about  the  ninth  thoracic 
vertebra  to  enter  the  right  azygos  vein,  receiving  veins  from 
three  or  four  lower  intercostal  spaces,  also  mediastinal  and 
esophageal  tributaries. 

The  left  upper  azygos^'  is  formed  by  veins,  usually  three  or 
four,  from  the  intercostal  spaces  between  the  left  superior  in- 
tercostal and  the  highest  branch  of  the  left  lower  azygos — ^.  e. 
from  the  fourth  space  to  the  seventh  or  eighth  inclusive— and 
empties  into  the  right  azygos  or  left  lower  azygos  ;  it  receives 
mediastinal  tributaries  and  the  left  bronchial  vein;  it  is  soma- 
times  absent,  its  place  being  taken  by  the  left  superior  inter- 
costal. 

Name  the  other  principal  veins  of  the  base  of  the  neck  ant 
of  the  thorax. 

Internal  mammary,  Mediastinal, 

Inferior  thyroid,  Pericardiac, 

Liter  costals.  Bronchial. 

Briefly  describe  the  spinal  veins. 

They  are  the  dorsi-.y>i,i(tl  on  the  exterior  of  the  spinal  col- 
umn, forming  plexuses  around  the  vertebral  spines,  laminae, 
and  processes,  emptying  into  the  vertebral,  intercostal,  lumbar, 
and  sacral  veins  respectively. 


218  ESSENTIALS  OF   HUMAN   ANATOMY. 

The  meningo-racMdian,  lying  between  the  vertebrae  and  theca 
spinalis,  forming  plexuses,  one  running  along  the  posterior  sur- 
faces of  the  vertebral  bodies,  forming  two  anterior  loiic/Ltadiual 
veins  receiving  the  venae  basis  vertebrarum,the  other  on  the  inner 
surfaces  of  the  lamina,  forming  two  posterior  longitadiiial  veins, 
both  extending  the  whole  length  of  the  spinal  canal ;  the  pos- 
terior emptying  into  the  dorsi-spinal,  the  anterior  into  the  ver- 
tebral, intercostal,  lumbar,  and  sacral  veins  respectively. 

The  vense  basis  vertehrarum  lie  in  the  vertebral  bodies  and 
empty  into  the  anterior  longitudinal  veins. 

The  medidli-spinal,  those  of  the  cord  itself,  form  a  minute 
plexus  over  the  cord  between  the  pia  mater  and  the  arachnoid, 
and  near  the  base  of  the  skull  converge  to  form  two  or  three 
trunks  terminating  in  the  inferior  cerebellar  veins  or  petrosal 
sinuses. 

Describe  the  chief  veins  of  the  lower  extremity. 

They  are  deep  and  superficial ;  the  former  commence  as  the 
venae  comites  of  the  digitals,  which  form  the  interosseous ;  these 
form  the  anterior^  posterior  tibial,  and  peroneal  comites  of  the 
same  named  arteries,  which  uniting,  form  the  popliteal,  in  the 
thigh  to  be  called  the  femoral,  being  joined  by  the  profunda 
femoris  and  the  internal  saphenous  veins,  which  again  changes 
its  name  to  the  external  iliac  above  Poupart's  ligament ;  into 
the  external  iliac  empty  the  deep  epigastric  and  deep  circum- 
flex iliac  veins. 

The  superficial  veins  are  the 

Internal  or  long  saphenous,  commencing  on  the  inner  side  of 
the  dorsum  of  the  foot,  running  up  in  front  of  the  inner  mal- 
leolus on  the  inside  of  the  leg  and  thigh  to  enter  the  femoral 
vein  after  passing  through  the  saphenous  opening  of  the  fascia 
lata  ;  its  tributaries  are  : 

Cutaneous,  Superficial  circumflex  iliac, 

Com.municating,  External  pudic, 

Superficial  epigastric,         Anterior  and  posterior  vein. 

External  or  short  saphenous  commences  at  the  outer  side  of 
the  dorsum  of  the  foot,  passes  behind  the  external  malleolus, 
and  up  the  middle  of  the  leg  posteriorly  to  empty  into  the  pop- 
liteal vein  between  the  heads  of  the  gastrocnemius. 


THE   VEINS.  219 

Describe  the  internal  iliac  vein. 

It  is  formed  by  the  venae  comites  of  all  branches  of  the  in- 
ternal iliac  artery  except  the  umbilical,  and  unites  opposite  the 
sacro-iliac  articulation  with  the  external  iliac  vein  to  form  the 
common  iliac  vein;  it  receives  the  following  veins: 

Gluteal,  Lateral  sacral, 

Sciatic  Uterine    and    vaginal  plexuses, 

Dorsal  vein  of  penis  or  clitoris,       in  female, 

Internal pudic,  Vesico-prostatic pdexus,  in  male, 

Obturator,  Hemorrhoidal  pdexus. 

The  portal  and  general  venous  systems  meet  in  the  hemor- 
rhoidal plexus. 

Describe  the  common  iliac  veins. 

Formed  by  the  junction  of  the  external  and  internal  iliac 
veins,  and  receiving  the  ilio-lumbar,  occasionally  the  lateral 
sacral,  the  left  iliac  receiving  the  middle  sacral  vein,  they 
unite  at  an  angle  upon  the  intervertebral  substance  between 
the  fourth  and  fifth  lumbar  vertebrae  to  form  the  inferior  vena 
cava. 

Describe  the  inferior  vena  cava^ 

It  runs  upward  from  the  junction  of  the  two  common  iliacs, 
along  the  riaht  side  of  the  aorta,  grooves  the  liver,  pierces  the 
central  tendon  of  the  diaphragm,  and  terminates  at  the  back 
and  lower  part  of  the  right  auricle,  being  enclosed  by  the 
serous  layer  of  the  pericardium  ;  it  returns  the  blood  from  all 
parts  below  the  diaphragm,  and  receives  the  following  tribu- 
taries : 

Tjiimlmr,  RenaP,^  Hepatic, 

Right  spermatic.     Right  suprarenal,       Right  common  iliac, 

Right  ovarian,        Inferior  jdirenic,        Left  common  iliac. 

Describe  the  portal  system  of  veins. 

Formed  by  the  union  behind  the  head  of  the  pancreas  of  the 
superior  and  inferior  mesenteric,  splenic,  and  gastric  veins,  col- 
lecting the  blood  from  the  viscera  of  digestion ;  the  resulting 
ported  vein  divides  in  the  transverse  fissure  of  the  liver  into  a 
branch  each  for  the  right  and  left  lobe,  which  ramify  to  form  a 
venous   plexus  in    the    liver-tissue;    the    hepatic   artery   sends 


220  ESSENTIALS  OF  HUMAN   ANATOMY. 

branclies  within  the  liver  to  the  portal  vein,  and  external  to 
the  organ  the  vein  receives  the  pyloric  and  the  coronary  veins ; 
the  portal  blood  is  returned  to  the  inferior  vena  cava  by  the 
hepatic  veins. 

Name  the  cardiac  veins. 

Anterior  or  ffreat  cardiac  vein,  Right  or  small  coronary  sinus, 
Middle  cardiac  vein,  Left  or  great  coronary  sinus, 

Left  or  posterior  cardiac  veins,      Venae  Thehesii. 
Right  or  anterior  cardiac  veins, 

What  is  the  coronary  sinus? 

A  dilatation  of  about  one  inch  of  the  anterior  cardiac  vein 
in  the  posterior  part  of  the  left  auriculo-ventricular  groove, 
covered  by  the  left  auricle,  receiving  the  posterior  and  middle 
cardiac  veins,  right  sinus,  and  an  oblique  vein  of  Marshall  from 
the  back  of  the  left  auricle ;  its  cardiac  orifice  is  guarded  by 
the  coronary  valve. 

Describe  the  pulmonary  veins. 

Commencing  in  the  lung  capillaries  they  form  a  main  vein 
for  each  lobule,  which  unite  into  two  trunks  for  each  lung, 
opening  separately  into  the  left  auricle  ;  at  times  there  are 
three  veins  on  the  right  side,  or  the  two  left  may  terminate 
by  a  common  opening. 

The  Lymphatics. 

What  are  the  lymphatics? 

Delicate  vessels  with  transparent  walls  formed  of  the  same 
three  coats  as  the  arteries  and  found  in  all  parts  of  the  body 
probably,  except  the  nails,  cuticle,  hair,  and  cartilage ;  they 
have  numerous  valves,  producing  their  characteristic  beaded 
appearance ;  they  are  supplied  with  nutrient  arteries,  but  not 
with  nerves. 

What  are  the  iacteals? 

The  lymphatics  of  the  small  intestine,  conveying  chyle 
during  digestion,  lymph  at  other  times. 

Describe  the  lymphatic  glands. 

They  are  small,  solid,  round,  or  oval  glandular  bodies,  situated 
Id  the  course  of  the  absorbent  vessels  which  previous  to  enter- 


THE   NERVOUS  SYSTEM.  221 

ing  a  gland  break  up  into  several  afferent  vessels^  form  a  plexus 
within,  and 'emerge  by  several  efferent  vessels  which  soon  unite 
to  form  a  single  trunk  ;  each  gland  is  surrounded  by  a  fibrous 
capsule  which  sends  partitions  inward,  forming  alveoli  in  which 
lies  the  gland-pulp,  or  lymphoid  tissue,  consisting  of  a  rete  whose 
meshes  are  filled  with  lymph-cells.  The  glands  are  chiefly 
found  in  the  mesentery,  along  the  great  vessels,  in  the  medi- 
astinum, axilla,  neck,  at  the  front  of  the  elbow,  groin,  and 
popliteal  space,  being  usually  named  from  their  locality,  as 
axillary  or  inguinal. 

Describe  tlie  thoracic  duct. 

This  conveys  the  bulk  of  the  lymph  and  chyle  into  the  blood, 
being  the  common  lymph-trunk  except  for  the  right  upper 
extremity,  right  side  of  the  head,  neck,  and  thorax,  right  lung, 
right  side  of  the  heart,  and  convexity  of  the  liver.  It  commences 
(sometimes)  by  the  triangular  recepta<uliun  chyli,  on  the  front 
of  the  body  of  the  second  lumbar  vertebra,  enters  the  thorax 
by  the  aortic  opening,  crosses  behind  the  aorta  at  the  fourth 
thoracic  vertebra,  and  opposite  the  upper  border  of  the  seventh 
cervical  vertebra  it  curves  downward  to  empty  into  the  junc- 
tion of  the  left  internal  jugular  and  subclavian  veins.  It  is 
from  fifteen  to  eighteen  inches  long  in  the  adult. 

Describe  the  right  lymphatic  duct. 

It  is  about  one  inch  long,  receiving  lymph  from  those  parts 
excepted  in  the  account  of  the  thoracic  duct,  and  empties  at  the 
junction  of  the  right  internal  jugular  and  subclavian  veins; 
both  ducts  have  double  semilunar  valves  at  their  orifices,  pre- 
venting regurgitation  of  blood. 

THE   NERVOUS   SYSTEM. 

What  are  the  two  divisions  of  the  nervous  system  ? 

The  cerehro-spinrd,  or  that  presiding  over  animal  life,  and  the 
sympathetic^  that  regulating  organic  life. 

Describe  the  structure  of  nerve-tissue. 

It  is  compo.sed  chiefly  of  two  structures :  the  gray  or  vesicn- 
l(ii\  originating  impulscH  and  receiving  impressions  ;  and  the 
white  or  yt7y/-c»i<s,  conducting  impressions;   in  the  sympathetic 


222  ESSENTIALS  OF  HUMAN  ANATOMY. 

system  is  found  a  third  structure,  gelatinous  nerve-tissue ;  75 
per  cent,  of  nerve-tissue  is  composed  of  water,  the  remainder 
being  albumin,  phosphorized  fat,  and  salts. 

Describe  the  microscopic  structure  of  white  nerve-tissue. 

It  is  formed  of  tubular  fibers,  each  consisting  of  a  central 
axis-cylinder,  surrounded  by  the  icliite  substance  of  ScJncaiin, 
the  whole  enclosed  by  the  tubular  membrane  ov  primitive  sheath. 
A  bundle  of  these  fibers  invested  by  a  fibro-areolar  membrane, 
the  perineurium  (neurilemma',  constitutes  a  nerve,  receiving 
a  special  blood-supply  by  the  vasa  nervorum  ;  the  gelatinous 
variety  consists  of  finely  granular  fibrillae  enclosed  in  a  sheath 
— by  some  these  are  not  considered  to  be  nerves. 

Describe  gray  or  vesicular  nerve-tissue. 

This  consists  of  large  granular  cells  containing  nuclei  and 
nucleoli,  ovoid,  or  with  one  or  many  processes  (^unipolar,  multi- 
polar), some  of  which  become  continuous  with  an  axis-cylinder. 

How  do  nerves  terminate  ? 

Peripherally  sensor}'  nerves  end  in  minute  plexuses,  end- 
bulbs,  tactile  corpuscles,  and  Pacinian  corpuscles;  in  the  special 
organs  they  end  in  cells  and  in  other  not  well-ascertained  ways; 
motor  nerves  end  peripherally  in  plexuses  or  by  "  motorial  encl- 
plates.^^     The  central  terminations  are  not  well  understood. 

What  organs  compose  the  cerebro-spinal  system? 

The  brain,  spinal  cord,  and  the  cranial  and  spinal  nerves. 

The  membranes  of  the  spinal  cord  and  brain  are  the  dura 
mater,  the  arachnoid,  and  pia  mater. 

Describe  the  cerebral  dura  mater  with  its  processes. 

It  is  a  dense  fibrous  membrane  lining  the  interior  of  the 
skull,  constituting  the  internal  periosteum,  is  continuous  with 
that  of  the  spinal  cord,  and  is  prolonged  to  the  outer  surface 
of  the  skull  through  the  various  foramina  ;  by  separation  of 
its  layers  the  cerebral  sinuses  are  formed  ;  its  smooth  under 
surface  is  covered  with  endothelial  cells ;  its  processes,  three 
in  number,  are  the 

Falx,  cerebri,  a  sickle-shaped  layer  occupying  the  longitudi- 
nal fissure  of  the  brain  :  along  the  upper  and  lower  border 
respectively  run  the  superior  and  inferior  longitudinal  sinuses. 


THE  NERVOUS  SYSTEM.  223 

Tentorium  cerehelli^  covering  the  upper  surface  of  the  cere- 
bellum ;  it  supports  the  weight  of  the  posterior  lobes  of  the 
cerebrum  ;  it  is  attached  to  the  horizontal  arms  of  the  occipital 
cross,  enclosing  the  lateral  sinuses,  to  the  upper  margins  of  the 
petrous  bones,  including  the  superior  petrosal  sinuses,  whence 
it  extends  to  the  anterior  and  posterior  clinoid  processes;  to 
the  mid-line  above  the  falx  cerebri  is  attached  antero-poste- 
riorly,  and  below  medianly  is  the  base  of  the 

Ftdx  cereheUi^  a  small  triangular  process  passing  vertically 
between  the  cerebellar  lobes  behind. 

What  are  the  Pacchionian  bodies  ? 

Numerous  aggregations  of  small  whitish  granulations  of  un- 
known function  found  upon  the  outer  surface  of  the  dura 
mater  near  the  superior  longitudinal  sinus,  lying  in  depressions 
in  the  bone,  in  the  superior  longitudinal  sinus,  on  the  inner 
surface  of  the  dura,  and  on  the  pia  mater  ;  unknown  in  infancy, 
rare  before  the  third  year  ;  they  are  enlargements  of  normal 
villi  of  the  arachnoid. 

Describe  the  arachnoid. 

It  is  a  delicate  membrane  lying  between  the  pia  mater  and 
the  dura  mater,  being  separated  from  the  latter  by  the  suhdnral 
space;  it  bridges  over  the  convolutions,  forming  |)rrr/  of  the 
siiharachnoidean  space,  and  at  the  base,  by  being  stretched 
between  the  middle  lobes,  the  anterior  siibarachnoulean  space 
is  left ;  while  between  the  cerebellar  hemisphere  and  the  medulla 
oblongata  lies  the  p)Osterior  siihavftclnioidean  space,  the  two  com- 
municating across  the  crura  cerebri,  and  by  an  opening  in  its 
lower  boundary  with  the  fourth  ventricle ;  these  spaces  con- 
tain the  cerebro-spinal  fluid,  forming  an  elastic  water-cushion 
for  the  encephalon  :  it  consists  of  interwoven  bundles  of  fibrous 
and  yellow  elastic  tissue  covered  with  a  layer  of  endothelium. 

What  is  the  pia  mater? 

It  consists  of  a  minute  plexus  of  blood-vessels  derived  from 
the  internal  carotid  and  vertebral  arteries,  held  together  by 
fine  areolar  tissue;  it  dips  between  the  convolutions,  helps  to 
form  the  vclnm  intcrpositum  and  choroid  phsxuses  of  the  third 
and  fourth  ventricles,  and  contains  nerves  and  lymphatics. 


224 


ESSENTIALS   OF   HUMAN   ANATOMY. 


Anterior  pri- 
mary vesi- 
cle, or  fore- 
brain 


'  First  secondary  vesi- 
cle (^proseitcepJia- 
loii) 


The  Brain. 

The  cerebral  part  of  the  cerebro-spinal  system  includes  the 
medulla  oblongata,  pons  Varolii,  cerebellum,  and  cerebrum.  The 
upper  end  of  the  neural  tube  develops  into  three  iwlmary 
vesicles;  next  the  anterior  and  posterior  vesicles  subdivide 
and  five  secoiidari/  vesicles  result,  each  having  a  cavity  and 
special  derivatives. 

The  brain  should  be  described  in  its  five  parts  : 

(  Anterior  end  of  the 
third  ventricle,  fora- 
mina of  Monro,  lat- 
eral ventricles,  cere- 
bral hemispheres, 
olfactory  bulbs  and 
tracts,  corpora  stri- 
ata, corpus  callo- 
sum,  fornix. 
Third  ventricle,  optic 
nerves  and  retinae, 
optic  thalami,  pit- 
uitary and  pineal 
bodies. 
Aqueduct  of  Sylvius, 
corpora  quadri- 

gemina,  crura  cere- 
bri. 

Cerebellum. 
Pons. 


Second        secondary 
vesicle     (jthalameii-  < 
cephaloii) 


Middle      pri- 
mary     vesi-  J  Third  secondary  vesi- 


cle, or  mid- 
brain 


cle  {inesencephaloii) 


3.  Posterior  pri- 
mary vesi- 
cle, or  hind- 
brain 


Fourth  secondary 
vesicle  (epeit- 
cep)lialo\i) 

Fifth      secondary 

vesicle       (jneten- 
ceplialo)i) 


Fourth 
ventri- 
cle 


Medulla  ob- 
longata. 


What  is  the  weight  of  the  brain? 

Forty-nine  and  a  half  ounces,  on  the  average,  in  males,  and 
forty-four  ounces  in  females ;  heaviest  male  brain  recorded, 
sixty-eight  and  three-eighths  ounces ;  lightest,  thirty-four 
ounces;  female  brain,  heaviest  fifty-six  ounces,  lightest  thirty- 
one  ounces ;  idiots'  brains  seldom  weigh  more  than  twenty- 
three  ounces. 


THE   BRAIN, 


225 


Name  the  fissures  and  lobes  of  the  cerebrum  (Fig.  108). 

Each  half,  or  hcmisjjJwre,  has  its  external  surface  subdivided 
into  five  lobes  by  three  fissures  : 

Fissure  of  Sylvius,  beginning  at  the  anterior  perforated  space, 
passes  to  the  external  surface  of  the  hemisphere  and  sub- 
divides :  one  arm  ascends  toward  the  frontal  lobe,  and  one  passes 
nearly  horizontalli/  backward  into  the  parietal  lobe. 

The  fissure  of  Rolando  commences  at  or  near  the  middle  of 
the  longitudinal  fissure,  running  downward  and  forward  to  a 
point  a  little  above  the  horizontal  branch  of  the  Sylvian  fissure. 

The  external  parieto-occipital  fissure  commences  about  mid- 
way between  the  posterior  extremity  of  the  brain  and  fissure  of 
Rolando,  running  downward  and  forward  for  a  few  millimeters. 

The  frontal  lobe  lies  in  front  of  the  fissure  of  Rolando,  and 
above  the  ascending  part  of  the  Sylvian  fissure ;  it  has  three 
surfaces ;  its  under  surface  is  called  the  orhital  lohe. 


Snd.  nf  CcUioSO 


ocafiita.L 

^fissure 


Fig.  108.— Convolutions  and  fissures  of  the  outer  surface  of  the  cerebral  hemi- 
sphere. 

Tlie  parietal  lohe  is  bounded  in  front  by  the  fissure  of  Ro- 
lando,  behind    by   the   external    parieto-occipital  ^fissure,   and 
below  by  the  liorizontal  limb  of  the  Sylvian  fissure, 
15 


22t)  ESSENTIALS   OE   HUMAN    ANATOMY. 

The  occipital  lohc  lies  behind  the  external  parieto-occipital 
fissure. 

The  teinjmro-sphenoidal  lohe  occupies  the  middle  cerebral 
fossa  of  the  skull,  and  is  limited  above  and  in  front  by  the 
Sylvian  fissure. 

The  central  lohc^  or  island  of  Reil,  lies  in  the  fisisure  of 
Sylvius  at  the  base  of  the  brain  ;  the  lobes  overlapping  it  are 
called  opercula. 

The  inner  or  median  surface  of  each  hemisphere  presents 
five  fissures  and  about  nine  gyri  or  convolutions  : 

The  calloso-inaryiiial  fissure  (Fig.  109),  separating  the  mar- 
ginal convolution  from  the  gyrus  fornicatus. 

The  internal  pmrieto-occiprital  fissure,  a  continuation  of  the 
external   on   the  outer  surface  of  the  hemisphere. 

The  calcarine  fissure  runs  from  the  back  of  the  hemisphere 
horizontally  forward  to  the  postero-inferior  extremity  of  the 
gyrus  fornicatus;  it  is  joined  by  the  internal  parieto-occipital 
fissure. 

The  collateral  fissure  runs  below  and  nearly  parallel  to  the 
preceding,  separated  by  the  infracalcarine  or  fifth  temporal 
gyrus. 

The  dentate  fissure  commences  below  the  posterior  extremity 
of  the  corpus  callosum,  running  forward  to  end  at  the  recurved 
part  of  the  hippocampal  gyrus,  the  uncus.  It  separates  the 
dentate  gyrus  from  the  hippocampal  gyrus. 

The  transverse  fissure,  between  the  temporal  lobes  and  crura 
cerebri,  fornix,  and  optic  thalami,  admits  the  pia  mater  into  the 
lateral  ventricles. 

Mention  the  principal  convolutions  of  the  brain. 

The  convolutions,  or  ff^ri,  are  elevated  ridges  covered  with 
gray  matter,  separated  by  deep  furrows,  or  sulci,  thus  securing 
a  great  extent  of  gray  matter  ;  while  not  uniform  in  all  brains, 
nor  symmetrical,  certain  principal  convolutions  are  constant, 
such  as 

The  gyrus  fornicatus,  that  lying  over  the  corpus  callosum. 

The  marginal,  forming  the  antero-superior  margin  of  the 
great  longitudinal  fissure  on  the  mesial  surface  of  the  hemi- 
sphere. 

The  uncinate  gyrus  includes  the  hippocampal  and  infra- 
calcarine gyri. 


THE  BRAIN. 


227 


The  limbic  lobe  nearly  forms  a  ring  around  the  corpus  callo- 
sum,  its  ends  being  separated  by  the  anterior  perforated  space ; 
the  structures  forming  it  are  the  gyrus  fornicatus,  hippocampal 
gyrus,  peduncles  of  the  corpus  callosum,  fascia  dentata,  fornix, 
the  anterior  and  posterior  pillars  of  the  fornix,  and  one  layer  of 
the  septum  lucidum.  Its  boundaries  are  the  calloso-raarginal, 
collateral,  and  post-limbic  fissures. 

The  ascending  frontal  (Fig.  108),  forming  the  anterior 
boundary  of  the  fissure  of  Rolando. 

The  ascending  parietal,  at  the  posterior  boundary  of  the 
same  fissure. 

The  angular  gyrus  is  a  part  of  the  inferior  parietal  convolu- 
tion, curving  around  the  extremity  of  the  superior  temporal 
sulcus. 

The  supramarginal  gyrus  lies  behind  the  lower  end  of  the 
intraparietal  sulcus,  arching  over  the  posterior  extremity  of 
the  fissure  of  Sylvius. 


Fig.  109.— Convolutions  and  fissures  of  the  inner  surface  of  the  cerebral 

hemisphere. 

Other  convolutions  are  indicated  by  the  names  on  the  dia- 
grams. 

Where   are   the   quadrate,  cuneate,  and   paracentral  lobes 

(Kig.  109)  ? 

The  former  is  on  the  mesial  surface  between  the  calloso-mar- 


228 


ESSENTIALS  OF  HUMAN   ANATOMY. 


ginal  fissure  in  front  and  the  internal  parieto-occipital  behind ; 
the  cuneate  lies  between  the  parieto-occipital  and  the  calcarine 
fissures ;  the  paracentral  is  on  the  mesial  surface  around  the 
upper  end  of  the  fissure  of  Rolando. 

Mention  structures  seen  on  the  under  surface  of  the  brain, 
in  the  middle  line,  and  on  each  side. 

Longitudinal  Jissure*   (Fig.    llOj,   partially    separating    the 
hemispheres. 


3        -  3 

Fig.  no.— Base  of  the  brain  (Leidy). 


Rostrum  and  peduncles  of  the  corpus  callosum,  which  is  the 
transverse  commissure  connecting  the  cerebral  hemispheres. 

Lamina  cincrea -passes  forward  from  the  tuber  cinereum  over 
the  optic  chiasma,  turns  upward  anterior  to  the  third  ventricle 


THE  BRAIN.  229 

as  the  lamina  fermi'nalis.  and  joins  the  anterior  end  of  the  corpus 
callosum.     The  angle  at  the  upward  bend  is  the  ojytic  recess. 

Optic  commissure'* J  union  of  the  optic  tracts,  with  their  par- 
tial decussation. 

Tuber  ctuereum,  an  eminence  of  the  gray  matter,  part  of  the 
floor  of  the  third  ventricle. 

Jn/iincUbulum^,  a  hollow  conical  p-rocess  of  the  gray  matter 
projecting  from  the  middle  of  the  under  surface  of  the  tuber 
cinereum,  communicating  with  the  third  ventricle,  joining  the 
posterior  lobe  of  the  pituitary  body. 

Pituitary  hody^  a  vascular,  two-lobed  body  projecting  from 
the  apex  of  the  infundibulum  into  the  sella  turcica  of  the 
sphenoid. 

Corpora  alhicantia^,  are  two  rounded  terminations  of  the  an- 
terior crura  of  the  fornix,  and  of  the  columns  of  Yicq  d'Azyr 
from  the  optic  thalami. 

Posterior  perforated  space^^,  between  the  corpora  albicantia 
in  front,  the  pons  Varolii  behind,  and  the  cerebral  crura  on 
either  side,  forms  part  of  the  floor  of  the  third  ventricle,  and 
gives  passage  for  vessels  to  the  optic  thalami.  It  is  the  ante- 
rior part  of  the  substantia  nigra. 

Tuber  annulare  of  the  pons^'  and  the  ventral  surface  of  the 
medulla  follow. 

Laterally  are  seen  the  frontal  lobe,  olfactory  bulb,  tract,  roots, 
and  the  optic  tract. 

Fissure  of  Sylvius*,  separating  by  its  horizontal  limb  the 
frontal  and  the  parietal  lobes  from  the  temporo-sphenoidal ; 
its  ascending  limb  passes  upward  into  the  inferior  frontal  con- 
volution. 

Anterior  jyerforated  space'',  between  the  roots  of  the  olfactory 
nerve  on  each  side  for  the  passage  of  vessels  into  the  corpus 
striatum. 

Crus  cerebri^^  (|)e<:/?/?tc7e  of  the  cerebrum)  connects  the  cere- 
brum with  the  cerebellum,  medulla  oblongata,  and  spinal  cord. 

Then  follow  the  lower  surfaces  of  the  temp>oral  lobe  and  of 
the  cerebellum.. 

Name  and  describe  the  basal  ganglia  of  the  hemispheres. 

Tlicy  arc  near  the  island  of  Jicil  and  form  the  oldest  part  of 
the  brain.  They  consist  of  the  eorjxn-a  sfrifffa,  the  clausfra,  and 
amygdaloid  nuclei,  the  optic  thalami  belonging  to  the  thalamen- 


230  ESSENTIALS  OF  HUMAN  ANATOMY. 

cephalon,  tsenia  semicircular  is,  external  and  internal  capsules, 
and  anterior  commissure. 

Corpora  striata,  chief  part  of  the  motor  tract,  lying  in  the 
lateral  ventricles,  the  intraventricular  gray  portion  called  the 
caudate  nucleus,  the  extraventricular,  the  lenticular  nucleus,  the 
internal  capsule  dividing  the  two. 

The  lenticular  nucleus  is  bounded  externally  by  the  external 
capsule,  and  that  externally  by  the  gray  matter  called  the 
claustrum.  The  caudate  nucleus  runs  downward  and  forward 
in  the  roof  of  the  descending  cornu,  and  terminates  in  the  nu- 
cleus amygdalse  in  the  apex  of  the  temporal  lobe. 

Each  optic  thalamus  has  two  rounded  extremities,  the  ante- 
rior and  the  posterior  tubercles,  the  latter  being  called  j^^dvinar, 
and  four  surfaces  ;  the  inferior  surface  rests  on  the  tegmentum 
of  the  crus  cerebri ;  the  external  is  in  contact  with  the  internal 
capsule  ;  the  internal  forms  the  lateral  boundary  of  the  third 
ventricle ;  the  upper  surface  presents  a  groove  for  the  margin 
of  the  fornix  ;  the  part  external  to  the  groove  is  on  the  floor 
of  the  body  of  the  lateral  ventricle;  the  part  internal  is  covered 
by  the  velum  interpositum.  Posteriorly  are  the  external  and 
internal  geniculate  bodies. 

The  tsenia  semicirailaris  lies  in  a  depression  between  the 
nucleus  caudatus  and  the  optic  thalamus.  In  front  it  joins 
the  anterior  pillar  of  the  fornix  ;  behind,  it  enters  the  nucleus 
amygdalae. 

What  is  the  internal  capsule  ? 

A  large  tract  of  white  matter  belonging  to  the  pyramidal 
tract,  consisting  of  two  limbs,  the  anterior,  lying  between  the 
anterior  part  of  the  lenticular  nucleus  and  the  caudate  nucleus, 
and  the  posterior,  lying  between  the  posterior  part  of  the  len- 
ticular nucleus  and  the  optic  thalamus,  which,  by  their  junction, 
form  a  projection  inward,  the  knee  or  genu. 

What  is  the  external  capsule  ? 

A  small  tract  of  white  matter  lying  between  the  outer  part 
of  the  lenticular  nucleus  and  the  claustrum. 

What  are  the  commissures? 

Connecting  bands  of  white  or  gray  matter.  Those  of  white 
matter  have  three  sets — 1 ,  project  ion- fibers,  which  pass  from 
the  mid-brain  to  the  hemispheres  and  form  the  corona  radiata ; 


THE   BRAIN.  231 

2,  transverse  or  commissural,  connecting  the  hemispheres  ;  3, 
associatwii-Jibers,  on  one  side  of  the  middle  line,  which  may  con- 
nect near  or  distant  parts ;  short  and  long  fibers  are  present, 
The  long  fibers  are  the 

Superior  longitudinal  fasciculus.  Uncinate  fasciculus, 

Inferior  longitudinal  fasciculus,  Fillet  of  the  gi/r  us  for  mea- 

tus, or  Cingulum, 
Perpendicular  fasciculus ,  Fornix. 

Other  longitudinal  bands  may  be  mentioned,  not  properly 
association-fibers — olfactory  tracts,  taenia  semicircularis,  crura 
cerebri,  peduncles  of  the  pineal  gland,  superior  .peduncles  of 
the  cerebellum,  gyrus  fornicatus. 

The  transverse  Jibers  of  the  white  matter  are  two  in  number 
— 1,  transverse  fibers  of  the  corpjis  callosum  ;  2,  antenor  com- 
missure. In  addition  are  the  middle,  posterior,  and  optic  com- 
missures, pons,  and  fornix. 

What  are  the  ventricles  of  the  brain  ? 

Five  serous  cavities,  four  of  which  intercommunicate ;  they 
are  two  lateral,  a  third,  ^fourth,  and  2^ fifth. 

Describe  the  lateral  ventricles. 

The  corpus  callosum  roofs  them  in  ;  each  has  a  hody,  an  an- 
terior cornu,  curving  outward  and  forward  into  the  frontal  lobe, 
a  middle  cornu  passing  into  the  temporal  lobe  /backward,  out- 
ward, f/ownward,  /orward,  and  mward  (J>odfi'),  containing  the 
curved  hippocampus  major,  and  a  jxjsterior  cornu  curving  back- 
ward and  inward  into  the  occipital  lobe,  containing  the  hippo- 
campus minor ;  the  floor  from  before  backward  is  formed  by 
the  corpus  striatum,  tffuia  semicircularis,  optic  tladamus,  cho- 
roid plexus,  corpus  fimJyriatuin,  half  of  the  hodij  and  the  pos- 
terior jn7/«r  of  the  fornix.     The  septum   lucidum  is  internal. 

What  are  the  pes  hippocampi  and  the  pes  accessorius  ? 

The  former  consists  of  elevations  of  the  lower  extremity  of 
the  hippocatnpus  major  in  the  floor  of  the  descending  cornu. 

P<s  accessorius,  or  «minenfia  collatcralis,  is  a  white  eminence 
external  to  the  hippocampus  major;  it  is  near  the  junction  of 
the  nii<l(ll(;  and  \\\v.  posterior  horns,  and  is  formed  by  the  inter- 
nal projection  of  the  collateral  fissure. 


232  ESSENTIALS  OF  HUMAN   ANATOMY. 

What  is  the  fascia  dentata? 

It  is  a  free  edge  of  the  gray  substance  of  the  dentate  convo- 
lution, seen  hy  raising  the  edge  of  the  corpus  fimbriatum. 

Describe  the  following  parts. 

Ol/dctorij  ljulbs''\  the  ganglia  of  the  sense  of  smell,  lie  in  the 
olfactory  grooves  of  the  cribriform  plate  of  the  ethmoid,  and  arise 
by  two  white  roots  :  the  ontn-  root  crosses  the  fissure  of  Syl- 
vius coming  from  a  nucleus  of  gray  matter  in  the  hippocampal 
gyrus  ;  the  inner  root  comes  from  the  lower  end  of  the  gyrus 
fornicatus;  and  the  middle  or  gray  root  comes  from  the  under 
surface  of  the  same  lobe. 

The  corjfiiH  ca/fosimi  is  a  thick  arched  layer  of  transverse 
fibers  at  the  bottom  of  the  longitudinal  fissure,  anteriorly 
curving  upon  itself,  giving  off  two  peduncles  to  the  entrance 
of  the  Sylvian  fissure;  posteriorly  is  the  spleninm  continuous 
with  the  fornix  ;  a  median  linear  depression  on  its  upper  sur- 
face is  called  the  raphe,  parallel  to  which  on  each  side  run  two 
or  more  elevated  longitudinal  bands,  the  strise,  hngitudinales  or 
nerves  of  Lancisi. 

Choroid  plexus  is  the  vascular  margin  of  the  velum  inter- 
positum,  communicating  with  that  of  the  opposite  side  just 
behind  the  anterior  pillars  of  the  fornix,  through  the  foramina 
of  Monro;  posteriorly,  it  descends  into  the  middle  horn, 
becoming  there  continuous  with  the  pia  mater  through  the 
transverse  fissure. 

Corpus  fimhriatum  (Jpfmia  hipjpjocarnjn)  is  the  lateral  edge 
of  the  posterior  pillar  of  the  fornix,  forming  a  white  band  just 
behind  the  choroid  plexus ;  it  is  attached  to  the  hippocampus 
major  and  ends  at  the  uncus. 

The  fornix,  continuous  with  the  corpus  callosum  behind, 
consists  of  two  halves  forming  a  triangular  hodi/,  two  anterior 
pillars,  curving  downward  to  the  base  of  the  brain,  there  to 
end  in  the  corpjora  alhicantia  and  not  in  the  optic  thalami,  and 
two  p)osterior  p)illars,  running  down  the  middle  cornua  of  the 
lateral  ventricles,  joining  the  hippocampn  majores  and  fmhi^ise  ; 
on  the  back  under  surface  of  the  corpus  callosum,  between  the 
posterior  pillars  of  the  fornix,  certain  transverse,  longitudinal, 
and  oblique  lines  have  been  termed  the  l?/ra. 

The  septum  lucid  inn  is  a  vertical  septum,  attached  above  to 
the  under  surface  of  the  corpus  callosum.  below  to  the  anterior 


THE  BRAIN.  233 

part  of  the  fornix  and  prolonged  portion  of  the  corpus  callosum  ; 
it  is  triangular  in  form,  and  consists  of  two  lamina  of  white 
nerve-matter  lined  internally  with  gray  matter,  the  space 
between  forming  the  Jifth  ventricle,  not  communicating  with 
the  other  ventricles. 
Describe  the  corpora  quadrigemina. 

These  are  four  rounded  projections  placed  just  behind  the  third 
ventricle  and  the  posterior  commissure,  beneath  the  posterior  bor- 
der of  the  corpus  callosum,  resting  on  the  lamina  quadrigemina, 
beneath  which  in  the  median  line  is  the  aqueduct  of  Sylvius. 
Two  white  bands  on  each  side  connect  them  with  the  geniculate 
bodies  and  ojyfic  tract;  that  passing  from  an  anterior  quadri- 
geminal  tubercle,  the  anterior  brachiuni,  goes  between  the  inter- 
nal geniculate  hodij  and  the  posterior  extremity  of  the  optic 
thalamus  to  the  external  geniculate  hodij  and  thence  to  the  optic 
tract.  The  posterior  hrachium  passes  from  a  posterior  quadri- 
geminal  tubercle  and  loses  itself  under  the  internal  geniculate 
body.  These  tubercles  seem  to  be  connected  with  the  cerebel- 
lum"^ by  the  superior  peduncles,  which  pass  to  the  optic  thalami 
through  the  tegmenta  of  the  crura. 

What  is  the  valve  of  Vieussens  ? 

A  thin  lamina  of  nerve-tissue,  stretching  from  the  vermiform 
process  of  the  cerebellum  from  one  superior  peduncle  to  the 
other,  forming  the  roof  of  the  upper  half  of  the  fourth  ven- 
tricle ;  a  little  ridge  descending  upon  the  upper  part  from  the 
corpora  quadrigemina  is  the  fr;£nuli an,  and  on  either  side  is  the 
fourth  nerve  ;  on  the  upper  surface  is  a  grooved  lobule  of  gray 
matter — the  lingula. 

What  is  the  pineal  gland? 

It  is  a  small  reddish  body,  epiphysis  cerebri,  behind  the  poste- 
rior commissure,  above  and  between  the  upper  pair  of  corpora 
quadrigemina ;  it  is  attached  on  each  side  by  a  st<dk  made  of  a 
dorsid  and  a  ventral  lamina  separated  by  the  pineal  recess  :  the 
former  belongs  to  the  posterior  commissure;  the  latter  is  pro- 
longed as  the  stria  pine<dis  to  the  anterior  pillar  of  the  fornix. 
Laterally  the  stalk  merges  into  the  trigonuin  habemdse,  a 
depression  on  the  upper  surface  of  the  optic  thalamus. 

Describe  the  third  ventricle. 

Narrow  and  oblong,  the  lateral  walls  being  the  optic  thalami 


234  ESSENTIALS  OF   HUMAN   ANATOMY. 

and  peduncles  of  tlie  pineal  gland  ;  above,  the  under  surface 
of  the  velum  iuterpositum  roofs  it  in,  containing  the  choroid 
plexuses  of  this  ventricle;  the  lamina  cinerea,  tuber  cinereum, 
infundibulum.  corpora  albicantia.  posterior  perforated  space, 
and  tegmenta  form  its  floor ;  it  is  limited  in  front  by  the  ante- 
rior crura  of  the  fornix  and  the  lamina  cinerea  ;  behind,  by  the 
posterior  commissure,  beneath  which  opens  the  aqueduct  of 
Sylvius;  while  in  front,  b}"  the  foramina  of  Monro,  it  com- 
municates with  the  lateral  ventricles  ;  the  cavity  is  crossed  by 
an  anterior  and  a  posterior  white  commissure  and  by  a  middle 
gray  commissure. 

Describe  the  fourth  ventricle. 

It  is  the  space  between  the  posterior  surface  of  the  medulla 
oblongata  and  the  pons  in  front  and  the  cerebellum  behind. 
Its  roof  is  the  superior  medullary  velum  or  valve  of  Vieussens, 
the  tent  and  the  inferior  medullary  velum  ;  the  lateral  boundaries 
on  each  side  are  above,  the  superior  peduncle  of  the  cerebellum, 
below,  the  clava  of  the  funiculus  gracilis,  funiculus  cuneatus,  and 
restiform  body ;  the  floor  is  diamond-shaped,  made  of  two  tri- 
angles, the  lower  belongs  to  the  medulla,  the  upper  to  the  pons  ; 
below  it  is  continuous  with  the  central  canal  of  the  cord,  above, 
with  the  aqueduct  of  Sylvius  ;  on  each  side  is  a  lateral  recess ; 
the  lower  end  is  called  the  calamus  scriptorius.  and  the  edge  of 
epithelium  on  the  margins  is  the  liyula,  and  at  the  calamus  is 
the  obex.  The  floor  is  bisected  by  a  median  groove,  from  the 
middle  part  of  which  arise  the  stri^  medullares,  running  trans- 
versely outward.  Below  them  are  three  triangles  on  each  side: 
internally  the  trigonum  hypogloasi,  or  fasciculus  teres;  exter- 
nally the  trigonum  acustici,  its  base  pointing  upward;  and  be- 
tween these  the  trigonum  vagi  with  its  apex  above.  This  apex 
is  the  inferior  fovea  ;  the  floor  and  base  are  the  ala,  cinerea 
and  the  eminentia  cinerea  ;  from  it  arise  the  ninth,  tenth,  and 
eleventh  cranial  nerves.  Above  the  striae  is  the  superior  fovea, 
to  its  inner  side  is  the  fasciculus  teres  continued  ;  above  the 
fovea  is  a  groove,  the  locus  coeruleus — the  color  is  due  to  the 
presence  of  pigmented  nerve-cells,  the  substantia  ferrvginea. 

Describe  the  pons  Varolii. 

It  is  the  ventral  portion  of  the  hind-brain,  the  cerebellum 
being  the  dorsal  ;  it  connects  the  medulla  below  with  the 
crura  cerebri.     It  is  about  one  inch  long ;  its  width  is  a  little 


THE   BRAIN.  235 

greater;  it  is  three-fourths  of  an  inch  thick.  It  has  four  sur- 
faces, the  svprrior  and  the  inUrior  seen  after  section,  the  ven- 
tral and  the  dorsal ;  the  dorsal  forms  the  upper  half  of  the  floor 
of  the  fourth  ventricle  ;  the  ventral  surface  rests  on  the  dorsum 
sellae  and  is  grooved  by  the  basilar  artery  ;  it  shows  well-marked 
transverse  fibers,  which  are  the  middle  peduncles  of  the  cere- 
helium,  or  the  tuber  annulare.  The  pons  has  gray  matter  and 
four  sets  of  white  fibers,  transverse  and  longitudinal,  with 
superficial  and  deep  sets  in  each.  The  gray  matter  contains 
the  nuclei  pant  is,  superior  olivary  nucleus^  nucleus  of  the  seventh, 
two  n  uclei  of  the  Ji/th,  and  nuclei  of  the  auditory  and  sixth  nerves. 

Describe  the  medulla  oblongata. 

The  medulla  or  spinal  bulb  is  the  after-Irani  connecting  the 
spinal  cord  with  the  pons  Varolii  and  cerebellum.  It  lies  in  the 
vallecula  between  the  cerebellar  hemispheres  and  rests  on  the 
basilar  groove  of  the  occipital  bone.  It  is  about  one  inch  long, 
three-c^uarters  of  an  inch  wide,  and  three-fifths  of  an  inch  thick  ; 
it  has  two  extremities  and  four  surfaces.  It  is  divided  into 
symmetrical  lateral  halves  by  the  anttrior  and  posterior  median 
fissures  (Figs.  110  and  111).  Each  lateral  surface  is  marked 
oif  by  a  dorso-lateral  Siud  a  ventro-lateral  groove. 

The  lower  half  of  the  ventral  surface  is  made  up  of  the  crossed 
pyramidal  tracts  of  the  cord,  decussation  of  the  j^yramids.  and 
laterally  by  the  direct  pyramidal  tracts.  Above,  in  the  upper 
half,  are  the  two  ^i^ramjWs ;  behind  each  pyramid  is  the 
ventro-lateral  groove. 

The  lateral  surface  presents,  above,  the  olivary  body  with  its 
dentate  nucleus  ;  below  is  the  lateral  tract,  containing  the  antero- 
lateral ground  bundle,  antno-lafered  ascending  and  descending 
cerebellar  tracts  of  the  cord.  Supeificial  arciform  JiLers  wind 
back  over  this  surface. 

The  dorsal  surface  is  divided  below  by  the  posterior  median 
fissure  and  separated  from  the  lateral  tract  by  the  dorso-lateral 
groove  ;  it  receives  the  direct  cerrhellar  tract  of  the  cord  pass- 
ing into  the  restiform  body.  Three  columns  are  between  this 
tract  and  the  median  fissure  :  externally  is  the  funiculus  of 
Rohmdo;  next,  the  funiculus  cunratus  ;  'iBnermost,  the  funiculus 
gracilis.  The  upper  half  of  the  dorsal  surf\\ce  is  the  lower  half 
of  the  floor  of  the  fourth  ventricle,  bounded  laterally  by  the  res- 
tiform bodies,  which  are  the  infrior  prd uncles  of  the  cerebellum. 


236 


ESSENTIALS  OF  HUMAN  ANATOMY. 


Describe  the  cerebellum. 

It  is  that  portion  of  the  hiiid-hraia  contained  in  the  inferior 
occipital  fossffi  composed  of  lamluse  covered  with  gray  matter ; 
in  the  middle  line  is  the  worm,  laterally  are  two  hemispheres. 
It  is  four  inches  wide,  two  inches  long,  and  about  two  inches 
thick ;  it  weighs  five  ounces ;  its  proportion  to  the  cerebrum 
is  as  1  to  8|-.  Above  is  a  median  ridge,  the  superior  vermi- 
form process  ;  below  is  a  median  fossa,  the  vallecula,  contain- 
ino-  the  inferior  vermiform  process.  In  front  and  behind  is  a 
notch,  the  incisura  cerehelli,  anterior  and  posterior ;  the  great 
horizontal  fissure  surrounds  the  cerebellum. 

Describe  the  lobes  and  sulci  of  the  cerebellum. 


Hemisphere. 


Worm. 


Worm  and 
Hemisphere. 


Sulcus  preoentralis 
Sulcus  postcentralis 
Sulcus  precllvalis  . 
Sulcus  postclivalis  . 


Lobus  lingulse. 


Frsenulum  lingulse.  Lingula. 

Ala  lobuli  centralis.  Lobulus  cen-  )  Lobus  cen- 

tralis, r     trails. 

Lobus  lunatus  ante-  Culmenmon-  I  Lobus  cul- 

rior  (crescentic).       ticuli.  (     minis. 

Lobus  lunatus  poste- Clivus    nion-  t  Lobus  clivi 
rior  (crescentic).        ticuli.  ( 


Lobus  postero-supe-  Folium  cacu 


.1 


Sulcus   horizontalis  )     "'^^- 
magnus / 


1-  Lobus       cacu- 
I     minis. 


Lobus  semilunaris  ^    Tuber  val- 
inferior.  b        vulse. 


Sulcus  postgracilis  . 


Sulcus  intragracilis 


Lobulus     gracilis  o 
posterior.  S- 


Lobulus     gracilis  2 
anterior.  ;;• 


Sulcus      pregracilis,  \  .'^ 

s.  postpyramidalis;  -^^— — — — ^-^^— ^-^— — ^ 

Sulcus    prepyrami da- Lobus    blventralis    Pyramis. 
lis     .   .   .   .* (digastric). 


Lobus  tuberis. 


(^  Lobus  pyrami- 
(     dis. 


Sulcus  postnodularis 


Amygdala  (tonsil).     Uvula. 


•Lobus  uvulse. 


Flocculus. 


Nodulus. 


^  Lobus  noduli. 


The  surfaces  of  the  cerebellum  present  lohes  and  interlohular 
fissures;  the  upper  surface  has  five  lobes  and  four  fissures  ;  from 


CRANIAL   TOPOGRAPHY.  237 

before  backward,  on  thp  superior  worm,  they  are  the  lingida,  loh- 
iilas  centralis,  cidmen,  clivis,  and  folium  cacuminis  ;  correspond- 
ing lobes  of  the  hemisphere  are  the  JriBiiulum,  ala,  anterior  and 
posterior  crescentic,  and  poster o-superior.  The  interlobular  fis- 
sures are  the  precentral,  postcentral,  preclival,  and  postclivaL  On 
the  lower  surface  are  four  lobes  and  three  fissures ;  from  be- 
hind forward  on  the  inferior  icorm  are  the  tuber  valvulse,,  pyra- 
mis,  uvula,  and  nodulus ;  on  the  hemisphere  are  the  jyostero-in- 
ferior,  divisible  into  the  inferior  semilunar,  posterior  and  ante- 
rior slender,  the  biventral  or  digastric^  the  amygdala^  and  the^oc- 
culus.  The  fissures  are  the  postp)yraniidal,  prepyraniidal,  and 
postnodular.  The  complete  arrangement  is  a  combination  of 
three  lobes,  one  on  each  hemisphere  and  one  on  the  worm, 
separated  from  similar  groups  by  fissures. 

How  many  peduncles  has  the  cerebellum? 

Three :  the  transverse  fibers  of  the  pons  Varolii,  or  middle 
peduncle;  on  each  side  the  restiform  bodies  of  the  medulla 
oblongata,  or  inferior  2)eduncles ;  the  superior  peduncles  run  to 
the  corpora  quadrigemina,  and  help  to  form  the  roof  of  the 
fourth  ventricle,  the  valve  of  Vieussens  lying  between. 

Describe  the  arrangement  of  the  gray  matter  of  the  cere- 
bellum. 

A  vertical  section  reveals  a  central  stem  of  white  matter 
containing  a  pouch  of  gray  matter,  the  corpus  dentatnm.  From 
the  central  white  stem  ten  or  twelve  plates,  or  hmiinse,  spring, 
covered  externally  by  a  layer  of  gray  matter,  so  that  the  cut 
surface  presents  the  appearance  called  arbor  vitse.  Special  nu- 
clei are  the  nucleus  emboliformis,  globosus,  fastigii,  or  nucleus  of 
the  roof. 

Cranial  Topography. 

Certain  important  advances  have  recently  been  made  in  cere- 
bral surgery  ;  the  student  of  anatomy  should  note  some  of  the 
contributing  causes,  such  as  the  localization  of  brain-centers 
and  their  relations  to  cranial  surfaces.  Certain  guide-points  are 
agreed  upon,  as  the  glabella,  the  smooth  eminence  between  the 
ridges  for  the  eyebrows;  nasion,  the  center  of  the  naso-frontal 
suture;  inion,  the  external  occipital  protuberance  ;  landxla,  at 
the  superior  angle  of  the  occipital  bone,  6  cm.  (nearly  2^ 
inches)  above  the  inion  ;  orbital  arch,  external  angular  process, 
mastoid   process,    external    auditory    meatus,    superior    nuchal 


238  ESSENTIALS  OF  HUMAN    ANATOMY. 

(curved)  line^  parietal  eminence,  zygoma^  sutures,  are  all  used 
as  landmarks. 

The  middle  meningeal  artery  is  opposite  a  point  in  the  tem- 
poral fossa  at  equal  distances,  one  inch,  one  and  a  half,  or  two 
inches  above  the  zygoma  and  the  same  distance  behind  the  ex- 
ternal angular  process  of  the  frontal  bone. 

The  mastoid  antrum  and  site  of  operation  on  the  same  is 
one-third  to  one-half  inch  behind,  and  the  same  distance  above 
the  center  of  the  external  auditory  meatus. 

Fissure  of  Rolando :  draw  a  line  from  the  naso-frontal 
groove,  nasion,  to  the  inion  ;  a  point  taken  on  this  line  1  cm.  (^ 
inch)  behind  its  center,  or  55.6  per  cent,  of  the  distance  from 
the  glabella,  will  indicate  the  superior  Rolandic  point.  Draw  the 
Rolandic  line  downward  and  forward  for  a  distance  of  8.6  cm. 
(o|-  inches),  at  a  Rolandic  angle  of  71.5'^  with  the  mesial  line, 
often  given  as  67°,  but  it  varies  from  6-1:°  to  75°.  If  the  inion 
cannot  be  easily  felt,  the  upper  end  of  the  llolandic  line  may  be 
practically  found  by  measuring  back  from  the  nasion  18  cm. 
in  case  of  large  heads,  17  cm.  in  small  ones.  The  fissure  of 
Rolando  is  not  quite  so  long  as  the  Rolandic  line,  and  the  ends 
of  the  fissure  do  not  quite  correspond  with  the  superior  and 
the  lower  Rolandic  points.  The  precentrcd  and  postcentral  sulci 
are  nearly  parallel  with  this  fissure,  and  15  mm.  distant. 

Another  method  is  Reid's :  he  first  marks  the  longitudinal 
fissure  and  horizontal  limb  of  the  fissure  of  Sylvius ;  Reid's 
base-line  passes  from  the  infraorbital  margin,  and  is  continued 
through  the  middle  of  the  external  auditory  meatus  ;  it  is  hor- 
izontal ;  from  it  are  (Jrawn  two  perpendicular  lines  to  the  top 
of  the  cranium  ,  one  from  the  preauricular  j^oint,  which  is  a 
depres.sion  between  the  tragus  of  the  ear  and  the  condyle  of 
the  jaw,  and  one  from  the  posterior  border  of  the  base  of  the 
mastoid  process.  A  four-sided  figure  is  thus  formed  and  a 
diagonal  from  its  postero-superior  angle  downward  to  the  an- 
terior perpendicular  line  where  it  crosses  the  fissure  of  Sylvius 
will  represent  the  fissure  of  Rolando. 

The  supjerior  Rolandic  point  may  be  found,  of  course,  by  the 
first  method,  and  only  one  vertical  line  of  Reid,  the  preauricu- 
lar, be  used  to  determine  the  lower  Rolandic  point. 

The  fissure  of  Sylvius  ('Reid's  description)  may  be  marked 
by  a  line  drawn  from  a  point  one  and  one-fourth  inches  behind 
the  external  angular  process  of  the  frontal  bone  to  a  point 


THE  SPINAL  CORD.  239 

three-fourths  of  an  inch  below  the  most  prominent  part  of  the 
parietal  eminence  ;  the  first  three-fourths  of  an  inch  represents 
the  main  fissure,  and  the  rest  the  horizontal  limb  ;  the  bifurca- 
tion of  the  fissure  is  therefore  two  inches  behind  and  slightly 
above  the  level  of  the  external  angular  process. 

Another  description  (Quain)  difiers  somewhat  from  the  above 
in  regard  to  measurements :  carry  a  horizontal  line  backward 
from  the  fronto-malar  junction  (external  angular  process;  for 
35  mm.  (1|^  inches),  and  from  the  outer  end  of  this  draw  a 
vertical  line  upward  for  12  mm.  (i  inch)  ;  the  upper  end  of 
the  latter  marks  the  Sylvian  j^oinf,  the  bifurcation  of  the  Syl- 
vian fissure ;  it  lies  under  the  posterior  part  of  the  sphenoparietal 
suture.  A  straight  line  drawn  from  the  fronto-malar  junction 
through  the  Sylvian  point  goes  to  the  lower  part  of  the  parie- 
tal eminence  and  about  overlies  the  posterior  limb  of  the  fis- 
sure ;  it  is  called  the  Sjjlvian  line.  The  ascending  limb  is 
marked  by  a  line  2  cm.  long,  starting  from  the  Sylvian  point 
directed  upward  and  forward,  at  a  right  angle  to  the  Sylvian 
line,  crossing  the  coronal  suture  obliquely  ;  the  undivided  main 
fissure  passes  horizontally  forward  beneath  the  spheno-parietal 
suture  in  the  region  of  the  pterion. 

The  lower  Roland ic  point  is  on  the  Sylvian  line,  25  mm.  be- 
hind the  Sylvian  point;  it  is  5.5  cm.  (4  to  7  cm.)  above  the 
zygoma  and  on  the  vertical  preauricular  line.  The  fissure  of 
Rolando  ends  about  1  cm.  above  this  spot. 

The  parallel  fissure  of  the  temporo-sphenoidal  lobe  is  indi- 
cated by  a  line  drawn  from  the  marginal  tubercle  on  the  pos- 
tero-superior  border  of  the  malar  bone  to  the  lambda. 

The  parieto-occipital  fissure  is  one-fifth  of  an  inch  above  the 
lambda,  or  6.5  cm.  (more  than  2\  inches)  above  the  inion; 
draw  a  transverse  line  of  2  cm.  to  represent  it. 

The  Spinal  Cord. 

What  is  the  spinal  cord? 

The  elongated  cylindrical  part  of  the  cerebro-spinal  axis  con- 
tained in  the  vertebral  canal,  measuring  sixteen  and  one-fourth 
to  seventeen  and  one-half  inches  in  length,  extending  from  the 
lower  margin  of  the  foramen  magnum  to  the  lower  border  of  the 
first  lumbar  vertebra,  presenting  a  cervical  enlargement  from  the 
third  cervical  to  the  first  or  second  thoracic  vertebra,  and  a 
lumbar  enlargement  opposite  the  two  or  three  last  thoracic  ver- 


240  ESSENTIALS  OF  HUMAN   ANATOMY, 

tebn«  ;  it  becomes  the  conns  medullaris  and  ends  by  a  filament, 
Jilnni  tcrniinale.  The  white  matter  is  disposed  externally,  the 
gray  internally  in  the  form  of  two  crescents  joined  by  a  trans- 
verse commissure,  the  anterior  thicker  extremities  forming  the 
anterior  cornna,  or  horiia,  the  posterior  forming  the  i^ostcrior 
coriiua. 

Describe  the  membranes  of  the  cord. 

Three  :  the  dura  mater,  continuous  with  that  of  the  brain, 
but  separated  from  the  bony  walls  by  loose  areolar  tissue,  con- 
taining a  plexus  of  veins  ;  the  arachnoid,  continuous  with  the 
cerebral  arachnoid,  also  having  a  snhdural  and  a  suharach- 
noidean  space,  the  latter  communicating  with  the  general 
ventricular  cavity  of  the  brain  by  the  foramen  of  3Iajemlie,  an 
aperture  in  the  pia  mater  of  the  fourth  ventricle — this  space 
contains  an  abundant  serous  secretion,  the  cerehro-spmal  flnid; 
and  the  pm  mater,  sending  a  fold  down  into  the  anterior 
median  fissure,  not  posterior,  having  medianly  in  front  a 
fibrous  band,  the  linca  splendent,  and  on  each  side  another,  the 
ligamentum  doiticulatiim,  whose  outer  border  presents  twenty- 
one  serrations,  the  apices  of  each  being  attached  to  the  inner 
surface  of  the  dura  mater,  serving  to  support  the  cord. 

Describe  the  fissures. 

They  are  the  anterior  and  the  posterior  median,  dividing  the 
cord  into  two  lateral  halves,  joined  by  a  white  and  a  gray  com- 
missure ;  on  each  side  of  the  anterior  fissure  is  a  series  of 
foramina  for  the  exit  of  the  anterior  roots  of  the  nerves ;  this 
line  of  openings  is  called  the  anterodateral  groove ;  a  postero- 
lateral groove  runs  parallel  to  the  posterior  median  fissure  on 
each  side  for  the  entrance  of  the  posterior  roots;  a  delicate 
groove  between  the  postero-lateral  groove  and  the  posterior 
median  fissure  exists,  the  posterior  mtermediate  furrow,  most 
marked  in  the  cervical  region. 

Name  the  columns  of  the  cord  marked  off  by  these  fissures. 
One  plan  is  to  make  three  columns  for  each  half — anterior, 
lateral,  and  posterior.  It  is  better  to  disregard  the  antero- 
lateral groove,  making  three  columns — antero-lateral,  postero- 
lateral, and  posterior  median.  The  antero-lateral  column 
includes  more  than  two-thirds  of  the  surface,  passing  from  the 
anterior   median    fissure   to    the    postero-lateral   groove ;    the 


THE  CRANIAL  NERVES. 


241 


postero-laferal  column  includes  the  part  between  the  postero- 
lateral groove  and  the  posterior  intermediate  furrow  ;  the  j^oste- 
rior  median  column  is  between  the  posterior  intermediate  fur- 
row and  the  posterior  median  fissure. 

What  is  the  ventricle  of  the  cord  ? 

The  fetal  central  canal,  usually  obliterated,  runs  in  the  gray 
commissure  the  whole  length  of  the  cord,  enlarged  below, 
and  opens  into  the  fourth  ventricle  above. 

The  Cranial  Nerves. 

Describe  them. 

The  cranial  nerves  number  twelve  pairs,  named  in  the  order 
of  their  passage  through  the  cranial  foramina;  other  names 
are  given  according  to  their 
function  or  distribution. 
Each  has  its  superficial  ori- 
gin, but  also  some  special  cen- 
ter, called  the  nucleus  :  this 
is  the  deep  or  real  origin. 

First,  Olfactory'  (Fig. 
Ill),  nerves  of  smell ;  super- 
ficial origin,  from  the  olfac- 
tory bulb,  a  lobe  of  the  brain, 
which  is  the  termination  of 
the  olfactory  tract,  having 
three  roots  (p.  232) ,  one  from 
the  temporal  lobe,  one  from 
the  frontal,  and  one  from  the 
gyrus  fornicatus ;  twenty 
non  -  medullated  filaments 
pass  in  three  groups  through 
the  foramina  in  the  cribri- 
form plate  to  the  upper  part 
of  the  nasal  mucous  mem- 
brane, to  the  cells  of  Schvltze. 

Second,  Optic",  nerve  of 
sight ;  deep  origin  Jvmn  the     ^^^  ^^^     ,^.,_^,  ^^^^.^^^  ,^^.^^.^,^  ^^  ^^^^  ^^^^ 
optic   tracts  "  ,    winch    arise  of  the  brain  (Lcidy). 

from  the  optic  thai  ami,  cor- 
pora geniculata;  and  superior  pair  of  the  corpora  quadrigemina ; 

16 


242 


ESSENTIALS  OF   HUMAN    ANATOMY. 


is  also  attached  to  the  cms  cerebri  and  receives  fibers  from  the 
tuber  cinereum  and  lamina  cinerea ;  in  front  of  the  tuber  cine- 
reum  lies  the  optic  chiasma  or  commissure,  formed  of  six  sets  of 
fibers,  viz.  a  set  crossing  from  the  right  side  of  the  brain  to  the  left 
eye  ;  a  second  pursuing  the  same  course  from  the  opposite  side, 
decussating  fibers  ;  a  third,  anterior,  connecting  the  two  retinae, 
interretiiial  fibers ;  a  fourth  and  fifth,  lateral,  cerebro-retinal, 
connecting  the  hemisphere  of  one  side  with  the  retina  of  the 
eye  of  the  same  side ;  a  sixth  intercerehral  set,  Gudden's  com- 


FiG.  112.— The  distribution  of  the  three  divisions  of  the  fifth  nerve  (Leidy). 

missure,  which  connects  the  internal  geniculate  bodies  and  the 
inferior  rjuadrigeminal  tubercles;  distribution,  retina. 

Third'".  Motor  oculi ;  superficial  origin,  inner  surface  of  the 
crus  cerebri ;  eleep  origin.,  a  nucleus  in  the  floor  of  the  aque- 
duct of  Sylvius  ;  escapes  in  two  branches  by  the  sphenoidal 
fissure  ;  distribution,  to  all  eye-muscles,  including  the  iris  and 
ciliary  mu.scle.  except  the  external  rectus  and  superior  oblique. 

Fourth  ''■,  Trochlear,  Patheticus.  motor ;  superficial  rjrigin, 
valve  of  Vieussens  ;  deep  origin,  floor  of  the  aqueduct  of  Syl- 


THE  CEANIAL  NERVES.  243 

vius ;  escapes  through  the  sphenoidal  fissure  ;  distribution^  to 
the  superior  oblique  of  the  eye. 

Fifth  '■,  Trigeminus  or  Trifacial,  nerve  of  general  sensation, 
motion,  and  perhaps  taste  ;  superjicial  origin^  by  a  motor  and  a 
sensory  root  from  the  side  of  the  pons  Varolii ;  deep  origin^ 
sensory  root  from  the  nucleus  in  the  pons  just  below  the  floor 
of  the  upper  half  of  the  fourth  ventricle  ;  the  Gasserian  gan- 
glion formed  on  this  root  lies  on  the  apex  of  the  petrous  por- 
tion of  the  temporal  bone  ;  the  motor  root  arises  from  a  mass 
of  gray  cells  to  the  inner  side  of  the  nucleus  of  the  sensory 
root;  escapes^  ophthalmic^  division  (Fig.  112),  by  the  sphe- 
noidal fissure,  superior  maxillary  *  by  the  foramen  rotundum, 
inferior  maxillary  °  by  the  foramen  ovale. 

Ophthalmic  division^  (Fig.  H-),  purely  sensory,  supplies 
the  eyeball,  ciliary  muscle,  iris,  lacrimal  gland,  nasal  and 
ocular  mucous  membrane,  skin  and  muscles  of  the  eyebrow, 
forehead  and  nose,  ciliary  ganglion  and  dura  ;  its  branches  are  : 

Frontal,  Lacrimal,  Nasal, 

Meningeal  or  (nervus  tentorii). 

Superior   maxillary    division*   (Fig.    112),    sensory,  is  dis- 
tributed to  the  temple,  cheek,  lower  ej^elid,  nose,  upper  lip  and 
teeth,  and,  by  ^leckel's  ganglion  connected  with  this  nerve,  to 
the  palate  and  pharynx  ;  its  branches  are  : 
Meningeal^  Two  sjyheno-jmlafine, 

Orbital  or  temporo-malar,  C  Palpebral, 

C  Anterior,  Infraorbital  <  Nasal, 

Superior  dental  I  Middle,  (^  Labial. 

(^  Postei'ior. 

Inferior  maxillary  division  ^  (Fig.  112),  nerve  of  common 
sensation  and  motion ;  supplies  the  muscles  of  mastication, 
teeth,  gums,  skin  of  the  temple  and  of  the  external  ear,  lower 
part  of  the  face  and  lower  lip,  the  tongue,  otic  and  sub- 
maxillary ganglia  ;  its  branches  are  : 

Meningeal  (iiervus  spmosus),  Auricnlo-temporal, 

Masseteric,  Lingual, 

Tliree  deep  temporal,  (  Mi/lo-Jnjoid, 


Buccal  (sf')iHor?/),  r  r    •       T     A   i\  Dental, 


rr,         .  -        -7  Inferior  dental 

Iwo  pterygoids,  -' 


hici^or, 
Mental. 


244  ESSENTIALS   UF   HUMAN    ANATOMY. 

Describe  the  cranial  and  facial  ganglia. 

The  Gassf ridii  gan(/liiin  is  convex  anteriorly,  rests  between 
two  layers  of  the  dura  in  the  cavum  M(  ckdli  on  the  apex  of 
the  petrous  portion  ;  under  it  are  the  motor  root  and  the  large 
superficial  petrosal  nerve  ;  it  gives  off  meningeal  branches  and 
three  divisions  of  the  fifth  nerve,  the  inferior  one  joining  the 
motor  root. 

The  ciliarij  or  oplitludmic  ganglion  is  in  the  orbit. 

The  sjjJieno-palatuie  ganglion  (Meckel's)  is  in  the  spheno- 
maxillary fossa. 

The  otic  ganglion  (Arnold's)  is  on  the  inner  side  of  the  infe- 
rior maxillary  nerve  below  the  foramen  ovale. 

Ganglia  are  occasionally  found  on  the  middle  meningeal, 
lingual,  temporal,  and  pharyngeal  arteries,  receiving  the  name 
of  their  location  or  discoverer,  as  Bidder  or  Cloquet. 

The  ganglion  of  Bochdalek  is  situated  in  the  external  wall  of 
the  antrum,  at  the  junction  of  the  middle  and  anterior  superior 
dental  nerves  from  the  infraorbital ;  the  ganglion  of  Valentin  is 
at  the  junction  of  the  middle  and  posterior  superior  dental. 

The  suhmaxillary  ganglion  lies  above  the  deep  portion  of  the 
submaxillary  gland. 

Describe  the  ciliary  ganglion. 

Situated  in  the  orbit  between  the  optic  nerve  and  the  external 
rectus  muscle  ;  its  roots  are  :  sensor ij^irom.  the  nasal  branch  of 
the  ophthalmic  (fifth  pair)  ;  motor,  branch  of  the  tLird  nerve  to 
the  inferior  oblique  muscle  ;  sympathetic,  cavernous  plexus  ;  its 
hranches  are :  short  ciliary  in  two  bundles  of  twelve  to  twenty 
twigs  to  the  ciliary  muscle,  iris,  and  cornea. 

Describe  the  spheno-palatine  ganglion. 

Deeply  placed  in  the  spheno-maxillary  fossa  ;  its  roots  are 
sensory,  from  the  superior  maxillary ;  motor,  facial,  through 
the  large  superficial  petrosal ;  sympathetic,  from  the  carotid 
plexus,  through  the  large  deep  petrosal ;   its  branches  are  : 

Ascending,  Pharyngeal,  or  Pterygo-palatine, 

Anterior  palatine,  Superior  nasal  (^anterior). 

Posterior  palatine,  Su2:>erior  nasal  (posterior), 

External  palatine,  Naso-palatine. 

Describe  the  otic  ganglion. 

It  lies  beneath  the  foramen  ovale,  internal  to  the  inferior 


THE  CRANIAL  NERVES.  245 

maxillary  nerve,  external  to  the  Elustachian  tube  and  in  front 
of  the  middle  meningeal  artery.  Its  motor  and  senmrij  roots 
come  from  the  nerve  to  the  internal  pterygoid,  sympathetic 
from  the  middle  meningeal  plexus  ;  it  connects  with  the  facial 
and  glosso-pharyngeal,  and  gives  a  sjyhenoidid  twig  to  the  A  idian. 
Branches  pass  to  the  auriculo-temporal,  chorda  tympani,  and 
buccal  nerves,  to  the  internal  pterygoid,  tensor  palati,  and  ten- 
sor tympani  muscles. 

Describe  the  submaxillary  ganglion. 

Situated  above  the  deep  portion  of  the  submaxillary  gland ; 
its  roots  are :  sensory,  from  the  lingual  nerve ;  motor,  facial, 
through  the  chorda  tympani ;  sympathetic,  from  the  facial 
plexus ;  its  branches  go  to  the  mucous  membrane  of  the 
mouth,  to  the  submaxillary  gland,  and  to  its  duct. 

Describe  the  petrosal  nerves. 

The  great  petrosal  (large  superficial  petrosal)  may  be  de- 
scribed as  a  branch  of  the  splieno-palatine  ganglion  passing 
through  the  Vidian  canal,  distributing  twigs  to  the  mucous 
membrane  of  the  back  part  of  the  nose,  septum,  and  p]ustachian 
tube,  passing  longitudinally  through  the  foramen  lacerum 
medium,  where  it  divides  into  the  large  superficial  petrosal, 
which  enters  the  hiatus  Fallopii,  receives  a  twig  from  Jacob- 
son's  nerve,  and  terminates  in  the  geniculate  ganglion  of  the 
facial  nerve,  and  the  carotid  (large  deep  petrosal)  joining  the 
carotid  plexus. 

Small  superficial  jietrosal  connects  the  geniculate  ganglion  of 
the  seventh  nerve  and  the  tympanic  plexus  with  the  otic  gan- 
glion. 

External  jyetrosal  (external  superficial  petrosal)  passes  from 
the  geniculate  ganglion  of  the  seventh  nerve  to  the  middle 
meningeal  plexus. 

More  correctly,  the  large  superficial  petrosal  and  the  large 
deep  petrosal  may  be  said  to  form  the  Vidian  nerve,  which 
runs  forward  through  the  same  named  canal  to  join  the  spheno- 
palatine ganglion,  supplying  it  with  motor  and  sympathetic 
fibers.  According  to  this  description,  the  twigs  said  to  be 
given  off  by  the  \'idian  nerve  to  the  nasal  mucous  membrane 
must  be  considered  branches  of  the  ganglion  running  back  in 
the  same  sheath. 


246  ESSENTIALS  OF  HUMAN  ANATOMY. 

Sixth,  Abducens"''  (Fig.  Ill),  motor;  sitperfjcial  origin^  he.- 
tween  the  anterior  pyramid  and  the  pons  Varolii ;  deep  origin^ 
from  the  nucleus  in  the  fasciculus  teres  on  the  upper  half  of 
the  floor  of  the  fourth  ventricle  ;  escapes,  by  the  sphenoidal 
fissure ;   distribution,  external  rectus  muscle. 

Seventh,  Facial^"  (Fig.  HI),  or  portio  dura  of  the  seventh 
nerve,  the  motor  nerve  of  all  muscles  of  expression,  of  the 
platysma,  buccinator,  the  muscles  of  the  external  ear,  posterior 
belly  of  the  digastric,  stylo-hyoid,  stapedius,  through  the  chorda 
tympani  the  lingualis,  according  to  some  through  the  great 
superficial  petrosal,  the  levator  palati,  and  the  azygos  uvulae 
muscles ;  supei-Jicial or igin  jmeduWsi,  from  the  groove  between  the 
olivary  and  restiform  bodies  ;  deep  origin,  from  the  nucleus  in 
the  formatio  reticularis  of  the  pons  below  the  floor  of  the  fourth 
ventricle  arching  over  the  nucleus  of  the  sixth  nerve ;  escapes 
by  the  internal  auditory  meatus  to  the  aqu^eductus  Fallopii, 
and  thence  by  the  stylo-mastoid  foramen  ;  distribution,  to  mus- 
cles already  mentioned  ;  its  branches  are  : 

Tympanic  (to  stapedius),  (  Temporal, 

Chorda  tympani,  Temporo-facial  X  Malar, 

Posterior  auricular,  {^Infraorbital, 

n*      /.•  (Buccal, 

u.   1    I     '-7  Cervico- facial  <  Suprar}iaxillary , 

l^atylo-hyoid,  ''  I   r  r  -n 

^       ^       '  {^InjramaxiUary. 

The  communications  of  the  facial  are : 

With  the  auditory  nerve :  Meckel's  ganglion  by  the  large 
superficial  petrosal ;  otic  ganglion  by  the  small  superficial 
petrosal ;  sympathetic  on  the  middle  meningeal  by  the  external 
petrosal  nerve ;  with  the  pneumogastric,  glosso-pharyngeal, 
carotid  plexus,  auricularis  niagnus,  auriculo-temporal,  and  with 
the  three  divisions  of  the  fifth  nerve. 

Eighth,  Auditory ''",  portio  mollis,  nerve  of  hearing ;  it  begins 
by  two  roots,  the  mesial  (anterior)  emerges  from  the  groove 
between  the  olivary  and  restiform  bodies  at  the  lower  border 
of  the  pons;  deep  origin,  dorsal  auditory  nucleus  under  the  tri- 
gonum  acustici ;  the  lateral  root  (posterior)  passes  around  the 
outer  side  of  the  restiform  body  and  appears  to  be  continuous 
with  the  striae  medullares ;  escapes  by  the  internal  auditory 
meatus  ;  distribution,  to  the  internal  ear ;  its  branches  are : 


THE  CRANIAL   NERVES,  247 

Vestibular,  to  the  vestibule, 
Cochlear,  to  the  cochlea  (see  p.  374). 

Ninth,  Glosso-ph.aryngeaP"'''  (Fig.  Ill),  nerve  of  common 
sensation  and  taste;  superjicial  or/^/y^,  medulla  in  the  groove 
just  behind  the  olivary  body  ;  deep  origin,  gray  nucleus  at  the 
inferior  fovea  in  the  lower  half  of  the  floor  of  the  fourth  ven- 
tricle ;  escapes  at  the  central  part  of  the  jugular  foramen,  after 
which  it  presents  two  gangliform  enlargements,  the  Jngular  and 
petrosal  ganglia;  distribution,  to  the  muscles  of  the  pharynx, 
mucous  membrane  of  the  pharynx,  fauces,  tonsil,  tongue,  and 
the  middle  ear  ;  its  branches  are  : 

Tympanic  (Jacobson's),       Pharyngeal,  Tonsillar, 

Carotid,  Muscular,  Lingual. 

Tenth,  Pneumogastric'^  (Fig-  HI),  nervus  vagvs,  has  an  ex- 
tensive distribution  both  motor  and  sensory  ;  superficial  origin, 
from  the  lateral  tract  of  the  medulla  oblongata  behind  the 
olivary  body  and  below  the  glosso-pharyngeal ;  deep  origin, 
ala  cinerea  in  the  lower  part  of  the  floor  of  the  fourth  ventricle 
— the  motor  filaments  probably  come  from  the  spinal  accessory  ; 
escaj)es  by  the  jugular  foramen,  presenting  a  gangliform  en- 
largement, ganglion  of  the  root,  and  lower  another,  ganglion  of 
the  trunk;  distrihution,  to  the  organs  of  the  voice  and  respira- 
tion, the  pharynx,  esophagus,  stomach,  and  heart ;  the  branches 
are : 

Meningeal,  Thoracic  cardiac, 

Anricidar,  Anterior  pidmonary, 

Pharyngeal,  Posterior  pulmonary^ 

Superior  laryngeal,  Esophageal, 

Recurrent  laryngeal,  Gastric, 

Cervical  cardiac.  Abdominal p>lexuses. 

Eleventh,  Spinal  accessory"',  is  a  motor  nerve,  spinal  part  to 
two  muscles,  accessory  part  to  the  vagus ;  superficial  origin, 
lateral  tracts  of  the  medulla  oblongata  below  the  roots  of  the 
vagus,  and  from  the  same  part  of  the  spinal  cord  to  the  fifth 
or  sixth  cervical  vertebra ;  deep  origin,  gray  matter  below  the 
nu(;]('us  of  the  vagus  and  int(!rmedio-lateral  tract  of  the  cord  ; 
it  sends  filaments  to  the  ganglion  of  the  root  of  the  vagus,  to 
the  pharyngeal  and  superior  laryngeal  branches  of  the  same 


248  ESSENTIALS  OF  HUMAN   ANATOMY. 

nerve  ;  escapes  by  the  jugular  foramen,  the  spinal  portion  first 
entering  the  skull  through  the  foramen  magnum  ;  disfri/nifion, 
to  the  sterno-mastoid  and  trapezius,  muscles  of  the  larynx,  of 
the  soft  palate,  except  the  tensor  palati,  constrictors  of  the 
pharynx,  inhibitory  fibers  to  the  heart. 

Twelfth,  Hypoglossal''"  (Fig.  Ill),  motor  nerve  of  the 
tongue  ;  Hiipcrjicidl  origin^  groove  between  the  pyramid  and  oliv- 
ary body  in  the  line  of  the  anterior  nerve-roots  ;  deep  origin.,  tri- 
gonum  hypoglossi  on  the  floor  of  the  fourth  ventricle ;  escapes 
by  the  anterior  condyloid  foramen  ;  branches  are  meningeal, 
vascular,  muscular  ;  latter  to  the  intrinsic  fibers  of  the  tongue, 
lingualis,  hyo-,  stylo-,  and  genio-hyoglossus ;  it  communicates 
with  the  tenth,  lingual,  three  upper  cervical,  and  sympathetic 
nerves ;  the  descendens  cervicalis  from  the  first  and  second  cer- 
vicals  runs  in  the  sheath  of  the  hypoglossal ;  the  communicans 
cervicalis,  rising  from  the  second  and  third  cervicals  meets  the 
descendens  in  a  loop,  ansa  cervicalis;  these  three  cervicals 
supply  the  genio-hyoid  and  the  infrahyoid  group  of  muscles. 

The  Spinal  Nerves. 

How  many  pairs  of  spinal  nerves  are  there  ? 

Eight  cervical,  twelve  thoracic,  five  lumbar,  five  sacral,  and 
one  coccygeal — thirty-one  in  all. 

Describe  their  origin. 

Each  nerve  arises  by  an  anterior  motor  root,  emerging  from 
the  antero-lateral  groove,  and  a  posterior  sensory  entering  the 
postero-lateral  groove  ;  these  perforate  the  dura,  the  posterior 
develops  a  ganglion,  and  they  unite  to  pass  through  the  inter- 
vertebral foramina — except  the  first  cervical,  which  emerges 
above  the  atlas — after  which  they  break  up  into  anterior  and 
posterior  divisions,  the  latter,  the  smaller,  supplying  the  spine, 
dorsal  muscles,  and  integument,  while  the  anterior  larger 
divisions  form  plexuses  whence  the  remainder  of  the  trunk 
and  the  limbs  receive  their  nerve-supply. 

Describe  the  cervical  plexus  with  its  branches. 

It  is  formed  by  the  anterior  divisions  of  the  four  upper  cer- 
vical nerves  lying  upon  the  levator  scapulae  and  scalenus 
medius  muscles  ;    its  branches  are  the    superfcial  and   deep : 


THE  SPINAL  NERVES. 


249 


Ascending 
Descending 


Svperjicialis  colli, 
Auricular  is  mag- 

uus, 
Occijjif ((lis  minor.  Internal    ^ 
Suprasterrud, 
Supraclavicula  /•, 
Supra-acromial. 

External 


''  Communicating , 
Muscular. 
Communicans  cer- 
vical is. 
Descendejis    cervi- 

calis, 
Phren  ic. 
j  Communicating, 
I  Muscular. 


Describe  the  phrenic  nerve. 

It  arises  cliiefly  from  the  fourth  cervical  nerve  with  branches 
from  the  third  and  fifth,  runs  obUquely  over  the  scalenus 
anticus  muscle,  passes  between  the  subclavian  artery  and 
vein,  enters  the  chest  anterior  to  the  internal  mammary  artery, 
to  be  distributed  to  the  pericardium,  pleura,  and  under  surface 
of  the  diaphragm  and  phrenic  plexus;  Luschka  describes 
twigs  to  the  peritoneum,  inferior  vena  cava,  and  right  auricle 
of  the  heart;  it  is  joined  by  filaments  from  the  sympathetic, 
from  the  nerve  to  the  subclavius  muscle,  and  one  from  the 
union  of  the  descendens  cervicalis  with  the  spinal  nerves. 

Describe  the  brachial  plexus  with  its  branches. 

It  is  formed  by  the  union  of  the  anterior  trunks  of  the  four 
lower  cervical  and  first  thoracic  nerves  ;  four  special  names  are 
used— anterior  nerves  form  trunks,  trunks  form  divisions  or 
branches  and  these  form  cords.  The  fifth  and  sixth  cervical 
nerves  join  and  form  an  upjyer  trunk  ;  the  eighth  cervical  and 
first  thoracic  unite  and  form  a  loicer  trunk  ;  the  seventh  remains 
single  and  forms  a  middle  trunk ;  each  trunk  divides  into  an  ante- 
rior find  a  posterior  division;  the  anterior  divisions  of  the  upper 
and  middle  trunks  unite  and  form  the  oiiter  cord;  the  anterior 
division  of  the  lower  trunk  forms  by  itself  the  inner  cord,  and 
the  posterior  divisions  of  all  three  form  the  posterior  cord; 
sometimes  the  posterior  division  of  tlie  lower  trunk  does  not 
meet  the  other  two,  but  runs  lower  down  into  the  musculo- 
spiral  nerve.  From  the  outer  cord  arise  the  external  anterior 
thoracic  nerve,  nerve  to  the  coraco-bracbialis,  musculo-cutaneous, 
and  the  outer  head  of  the  median  ;  from  the  inner  cord  arise  the 
internal  anterior  thoracic,  lesser  internal  cutaneous,  internal 
cutaneous,  ulnar,  and  inner  head  of  the  median  ;  from  the  ^>as- 


/ 


250  ESSENTIALS  OF  HUMAN   ANATOMY. 

terior  coy(/ arise  three  subscapular  nerves,  the  circumflex,  and  the 
musculo-spiral.  Branches  of  communication  are  with  the  fourth 
cervical,  second  thoracic,  phrenic,  and  sympathetic  system  ; 
hrancJiea  of  clistrihutioa  are  (I)  to  the  muscles  of  the  trunk, 
(II)  of  the  shoulder  girdle,  and  (III)  of  the  upper  extremity. 

(I)  Mmcular  to  the  longus  colli  and  three  scaleni ;  lower 
part  of  scalenus  anticus  and  medius  ;  whole  of  scalenus  posticus. 

(II)  1.    Twig  to  the  rhomboidei  from  the  fifth  cervical. 

2.  Posterior  or  long  thoracic^  from  the  fifth,  sixth,  and 
seventh  nerves,  to  the  serratus  magnus  muscle. 

3.  Suprascapular,  from  the  upper  trunk  ;  to  the  supra  and 
infraspinatus  muscles  and  shoulder-joint. 

4.  Nerve  to  the  subclavius  from  the  upper  trunk,  mainly  from 
the  fifth. 

5.  External  and  internal  anterior  thoracic,  the  former  from 
the  outer  cord,  the  latter  from  the  inner  cord  ;  both  to  the 
pectoralis  major,  the  internal  to  the  pectoralis  minor. 

6.  Three  subscapular,  the  upper  from  the  communicating 
branch  from  the  outer  to  the  posterior  cord,  the  other  two 
from  the  posterior  cord  ;  to  the  subscapularis,  teres  major,  and 
latissimus  dorsi  muscles. 

7.  Circumflex,  from  the  posterior  cord  with  the  musculo- 
spiral  ;  to  the  deltoid  and  teres  minor,  the  shoulder-joint,  and 
skin  of  the  lower  deltoid  region. 

8.  Xerve  from  the  outer  cord  to  the  coraco-hrachial is. 

(III)  There  are  five  anterior  arm-nerves,  one  posterior  ;  mus- 
culo-cutaneous,  from  the  outer  cord  pierces  the  coraco-brachialis  ; 
to  biceps,  brachialis  anticus,  and  elbow-joint,  and  skin  of  the 
outer  surface  of  the  forearm  ;  internal  cutaneous,  from  the  inner 
cord  to  the  skin  over  the  biceps  and  that  of  the  inner  half  of  the 
forearm  in  front  and  behind  ;  lesser  internal  cutaneous  (nerve  of 
Wrisberg),  from  the  inner  cord  alone,  or  a  branch  from  this 
joined  with  the  intercosto-humeral,  the  lateral  cutaneous 
branch  of  the  second  intercostal  nerve  ;  or,  again,  the  intercosto- 
humeral  may  entirely  replace  it;  to  the  skin  of  the  inner  side  of 
the  arm  ;  median,  from  the  outer  and  inner  cords  by  two  roots 
that  embrace  the  axillary  artery,  uniting  in  front  or  to  its  outer 
side,  first  lying  external  to  the  brachial  artery,  then  crossing  to 
its  inner  side,  passing  between  the  two  heads  of  the  pronator 
teres  muscle  to  run  between  the  deep  and  superficial  flexors 
of  the  fingers  to  near  the  wrist,  where  it  becomes  superficial ; 


THE  SPINAL   NERVES.  251 

its  branches  are  articalm-  to  the  elbow,  wrist,  metacarpus,  and 
fingers ;  mascidar^  to  all  anterior  superficial  forearm-muscles 
except  the  flexor  carpi  ulnaris  ;  anterior  interosseous,  to  the  deep 
forearm-muscles  except  the  inner  half  of  the  flexor  profundus 
digitorum  ;  palmar  cutaneous,  piercing  the  fascia  above  the  wrist 
to  the  skin  of  the  thenar  eminence ;  branches  to  the  abductor, 
opponens,  and  outer  head  of  the  flexor  brevis  pollicis  ;  Jive  digi- 
tals, supplying  both  sides  of  the  thumb,  index,  middle,  and  radial 
side  of  the  ring  fingers. 

Ulnar,  from  the  inner  cord  runs  behind  the  inner  epicondyle, 
passing  into  the  forearm  between  the  heads  of  the  flexor  carpi 
ulnaris  to  run  some  distance  from  the  ulnar  artery  at  the  upper 
third,  but  clo.se  to  it  for  the  rest  of  its  extent ;  it  supplies  both 
sides  of  the  little  and  ulnar  side  of  the  ring  finger  and  skin  in- 
ternally of  the  forearm  and  hand  ;  its  branches  are  articular 
for  the  elbow,  wrist,  metacarpus,  and  hand  ;  muscular,  to  the 
flexor  carpi  ulnaris,  inner  half  of  the  flexor  profundus  digito- 
rum, the  little  finger  muscles,  the  interossei  and  inner  two 
lumbricals,  palmaris  brevis,  adductores  pollicis,  and  inner  head 
of  the  flexor  brevis  pollicis. 

Names  of  branches  in  the  forearm  are  :  Articular,  muscular, 
cutaneous,  dorsal  cutaneous ;  in  the  \i\}in^\,  superficial  and  deep 
palmar. 

Musculo-spiral,  from  the  posterior  cord,  runs  in  the  spiral 
groove  with  the  superior  profunda  vessels  to  divide  in  front  of 
the  external  condyle  of  the  humerus  into  the  radial  and  poste- 
rior interosseous  ;  its  branches  are  : 

Radial,  Muscular, 

Posterior  interosseous.  Cutaneous, 

Articular  (elbow  and  wrist). 

Radial,  to  the  skin  of  the  ball  of  the  thumb,  to  back  of  the 
thumb  as  far  as  the  nail,  back  of  first  phalanx  of  the  index 
finger,  arnl  back  of  the  radial  half  of  the  first  phalanx  of  the  mid- 
dle finger;  posterior  interosseous,  supplying  the  wrist-joint  and 
all  muscles  on  the  back  of  the  forearm  except  the  anconeus, 
supinator  longus,  and  extensor  carpi  radialis  longior;  muscular, 
to  the  triceps,  anconeus,  supinator  longus,  exten.sor  carpi  radialis 
longior,  and  brachialis  anticus  ;  cutaneous,  to  the  skin  of  the 
outer  and  Ijack  part  of  the  arm  and  forearm. 


252  ESSENTIALS  OF   HUMAN   ANATOMY. 

The  Thoracic  Nerves. 

Describe  them. 

Twelve  in  number  on  eacli  side,  the  first  escapes  between 
the  first  and  secund  thoracic  vertebrc^,  the  last  between  the 
last  thoracic  and  first  lumbar ;  they  divide  into  an  ante- 
rior and  a  posterior  division,  the  latter  supplying  the  spine, 
extensor  muscles  of  the  back,  and  the  dorsal  integument ; 
the  former  (anterior)  are  the  intercostal  nerves^  the  twelfth 
being  called  subcostal,  each  connected  by  one  or  two  filaments 
with  the  adjacent  sympathetic  ganglion  :  the  anterior  division 
of  the  Jirst  nerve  aids  in  the  formation  of  the  brachial  plexus; 
its  intercostal  branch  is  small  and  gives  ofi"  no  lateral  cutaneous 
branch  ;  the  lateral  branch  of  the  second  nerve  is  the  intercosto- 
humeral ;  the  nerves  give  off  lateral  and  anterior  cutaneous 
branches  supplying  the  skin  of  the  front  and  sides  of  the 
thorax  and  abdomen,  while  they  give  muscular  branches  to  the 
intercostal  and  abdominal  muscles. 

Describe  the  lumbar  nerves. 

The  posterior  branches  resemble  in  origin  and  arrangement 
those  of  the  thoracic  region,  while  their  anterior  branches  form 
the  lumbar  and  part  of  the  sacral  plexuses  ;  there  are  five 
pairs. 

Describe  the  lumbar  plexus  and  branches. 

It  is  formed  by  loops  of  communication  between  the  anterior 
divisions  of  the  four  upper  lumbar  nerves  in  the  substance  of 
the  psoas  muscle,  thus  the  first  lumbar  is  joined  by  a  branch 
from  the  last  thoracic,  dorso-lumhar,  and  gives  off  the  ilio- 
hijpogastric  and  ilio-inguinal  and  a  branch  to  the  genito-crural ; 
the  second  goes  to  the  genito-crural  and  external  cutaneous  and 
gives  a  descending  branch  to  the  anterior  crural  and  obturator  ; 
the  third  gives  off  three  branches,  one  to  the  extermd  cutaneous, 
a  large  one  to  the  anterior  crural,  and  one  to  the  obturator ; 
the  fourth  has  three  branches,  to  the  anterior  crural,  to  the 
obturator,  and  one  to  join  the  fifth,  forming  the  lumbosacral 
cord ;  the  fourth  is  called  the  nervus  furcalis,  splitting  like  a 
fork  for  the  two  plexuses ;  the  accessory  obturator  when 
present  comes  from  the  third  and  fourth  nerves. 

Branches  of  the  plexus  are:  1.  Of  communication  with  the 
twelfth  thoracic,  fifth  lumbar,  and  sympathetic.     2.   Of  disti-i- 


THE  SPINAL  NERVES.  253 

button,  short  set  to  the  quadratus  lumborum.  to  the  psoas  magnus 
or  parvus  ;  long  set  to  the  abdomen  and  to  the  thigh,  viz.  the 
ilio-hi/pogastric^illo-ingiiinal,  genital  part  of  the  genito-crural  to 
the  abdomen  ;  the  anterior  crural,  external  cutaneous,  crural 
part  of  the  genito-crural  and  obturator  to  the  thigh. 

llio-hypogastric  supplies  the  skin  of  the  gluteal  region,  skin 
and  two  muscles  of  the  hypogastrium,  the  internal  oblique  and 
trans versalis  ;  Uio-inguinal,  to  the  internal  oblique  and  trans- 
versalis  muscles  and  skin  of  the  scrotum  (labium  in  the 
female),  and  the  upper  inner  part  of  the  thigh  ;  external  cuta- 
neous, to  the  skin  of  the  antero-external  and  posterior  surfaces 
of  the  thigh  ;  genito-crural,  to  the  cremaster  muscle  and  skin 
of  the  front  of  the  upper  part  of  the  thigh  ;  obturator,  to  the 
obturator  externus  and  adductor  muscles,  hip-  and  knee-joints, 
also  sometimes  to  the  skin  of  the  thigh  and  leg. 

The  accessory  obturator  is  usually  lacking ;  when  present  it 
comes  from  the  third  and  fourth  lumbar  nerves,  crosses  the 
horizontal  ramus  of  the  pubes,  and  divides  into  three  branches  : 
one  to  the  hip-joint,  one  to  the  pectineus,  and  one  to  join  the 
obturator  nerve. 

Anterior  crural,  from  the  third  and  fourth,  with  a  communi- 
cating branch  from  the  second  lumbar  nerve.  It  descends 
beneath  Poupart's  ligament  external  to  the  femoral  artery  be- 
tween the  psoas  and  iliacus  muscles,  and  divides  into  an  ante- 
rior and  a  posterior  division  :  its  branches  are,  within  the  pelvis, 

Muscular  to  iliacus,  and  to  the  walls  of  the  femoral  artery  ; 
external  to  the  pelvis, 

.    ,     .        C  Middle  cutaneous,  t>    ^     •       C  Long  saphenous, 

Anterior    )   j  ,        j     ^  '  Posterior   )    4   .■    j^ 

,.    •  •  <  J nternat  cutaneous,  j-    •  •  i  Articutar, 

division.     ]   ^r       1  division.     ]    ,.        ,     ' 

(^  Muscular.  [^  Muscular. 

It  supplies  all  the  anterior  thigh-muscles,  except  the  tensor 
fasciae  femoris,  and  the  skin  of  the  front  and  inner  side  of  the 
thigh,  leg,  and  foot. 

The  muscular  branches  of  the  anterior  division  supply  the 
pectineus  and  sartorius ;  the  muscular  branches  of  the  poste- 
rior division  supply  the  quadriceps  femoris ;  the  nerve  to  the 
rectus  sends  a  filament  to  the  hip-joint,  the  nerves  to  the  vasti 
•send  filaments  to  the  knee-joint. 

Describe  the  sacral  plexus. 

It  is  formed   l^y  the  lumbo-sacral  cord  (the  anterior  division 


254  ESSENTIALS  OF   HUMAN    ANATOMY. 

of  the  fifth  lumbar  nerve  with  a  branch  of  the  fourth),  and 
anterior  divisions  of  the  three  upper  sacral  nerves  and  part  of 
that  of  the  fourth  ;  it  rests  upon  the  anterior  surface  of  the 
pyriformis  muscle,  giving  off  the 

Superior  gluteal,  from  the  lumbo-sacral  cord,  passing  out 
through  the  greater  sacro-sciatic  foramen,  to  the  gluteus  medius 
and  minimus  and  tensor  fasciae  femoris  muscles;  the  inferior 
gluteal  nerve  supplies  the  gluteus  maximus. 

Muscular  hranches  to  the  pyriformis,  obturator  internus  and 
superior  gemellus,  to  quadratus  femoris  and  inferior  gemellus. 

Pndic  passes  out  of  the  pelvis  by  the  greater  sacro-sciatic 
foramen,  to  re-enter  it  by  the  lesser  sacro-sciatic  foramen ;  its 
branches  are  : 

Inferior  hemorrhoidal.       Perineal,       Dorsal  of  peiLis. 

Muscular,  to  the  transversus  perinei,  accelerator  urinae, 
erector  penis,  compressor  urethras,  levator  ani,  and  external 
sphincter :  the  preceding  branches  supply  analogous  muscles 
and  parts  in  the  female. 

Smcdl  sciatic  escapes  by  the  greater  sacro-sciatic  foramen,  to 
the  skin  of  the  scrotum,  lower  part  of  the  buttock,  back  of  the 
leg  and  thigh  ;  its  branches  are  the  gluteal  cutaneous,  femoral 
cutaneous,  and  inferior  pudendal ;   no  muscular  branches. 

Great  sciatic  is  a  continuation  of  the  main  part  of  the  sacral 
plexus,  forming  the  largest  nerve  in  the  body.  Escaping  by  the 
greater  sacro-sciatic  foramen  below  the  pyriformis  muscle,  it  lies 
in  a  groove  between  the  great  trochanter  and  the  tuber  ischii, 
covered  by  the  gluteus  maximus,  resting  on  the  obturator  in- 
ternus, gemelli.  and  quadratus  femoris :  its  branches  are  articu- 
lar to  the  hip,  muscular  to  the  biceps,  semitendinosus,  semimem- 
branosus, and  adductor  magnus,  and  it  divides  into  the  internal 
and  the  external  popliteal  nerves. 

Name  the  branches  of  the  internal  popliteal  nerve. 

Articular  to  the  knee,  three  in  number. 

Muscular  to  the  gastrocnemius,  plantaris,  soleus,  and  pop- 
liteus. 

External  or  sliort  saphenous  is  formed  by  the  junction  of  a 
cutaneous  branch,  communicans  tibialis  or  poplitei,  and  another 
cutaneous  branch  of  the  external  popliteal,  the  communicans 
fbularis  or  peronei. 


THE  SPINAL   NERVES.  255 

Describe  the  posterior  tibial  nerve. 

It  is  a  continuation  of  the  former,  runs  down  the  middle  of 
the  back  of  the  leg  beneath  the  calf-muscles  to  divide  between 
the  inner  malleolus  and  point  of  the  heel  into  the  internal  and 
external  plantar  ;  its  branches  are  : 

Mascnlur^  to  the  tibialis  posticus,  flexor  luiigus  digitorum, 
flexor  longus  hallucis,  and  the  soleus  muscles ;  articular^  to 
the  ankle-joint. 

Plantar  cutaneous^  to  the  skin  of  the  heel  and  inner  side  of 
the  sole  of  the  foot. 

Fibular  branchy  to  the  vessels,  periosteum,  and  medullary 
canal  of  the  fibula. 

Internal  plantar,  supplying  the  skin  of  the  sole,  tarsal  and 
metatarsal  joints,  one  or  two  inner  lumbricals,  abductor  hallu- 
cis, flexor  brevis  hallucis,  and  digitorum,  four  digital  branches 
to  both  sides  of  the  first,  second,  and  third  toes,  and  inner  half 
of  the  fourth. 

External  plantar,  smaller  than  the  preceding,  supplying  the 
flexor  accessorius,  abductor,  and  flexor  brevis  minimi  digiti,  all 
the  interossei,  two  or  three  outer  lumbricals,  adductor  obliquus, 
and  transversus  hallucis.  and  the  skin  of  the  little  toe  and  the 
adjoining  side  of  the  fourth  toe. 

Describe  the  external  popliteal  nerve. 

It  descends  obliquely  along  the  outer  side  of  the  popliteal 
space  close  to  the  tendon  of  the  biceps,  giving  off 

Three  articular  branches  to  the  knee  ;  a  cutaneous  branch  to 
the  skin  of  the  postero-external  surface  of  the  leg,  and  a  branch, 
the  communlcans  peronel,^ovu\m<^^[)iTt  of  the  external  saphenous 
nerve  :  it  divides  into  the 

Anterior  tibial,  about  one  inch  below  the  head  of  the  fibula, 
giving  mnscular  branches  to  the  tibialis  anticus,  extensor  longus 
digitorum,  peroneus  tertius,  extensor  longus  hallucis,  and  ex- 
tensor brevis  digitorum  ;  articular  to  the  tarsal  and  metatarsal 
joints,  and  cutaneous  to  the  skin  of  the  adjacent  sides  of  the 
great  and  second  toes. 

Musculo-cutaneous,  giving  off  muscular  branches  to  the  pero- 
neus longus  and  brevis,  and  ciitaneons  to  the  skin  of  the 
lower  part  of  the  leg,  and  dorsum  of  the  foot  and  toes,  except 
the  outer  side  of  the  little  and  adjoining  sides  of  the  great  and 
second  toes. 


256  ESSENTIALS  OF   HUMAN   ANATOMY. 

Describe  the  sacral  and  coccygeal  nerves. 

They  arc  six  in  number,  their  long  roots  forming  the 
Cauda  equina  in  the  spinal  canal ;  each  divides  into  an  ante- 
rior and  a  pos^eno?"  division,  the  latter  escaping  by  the 
posterior  sacral  foramina,  except  the  fifth,  which  emerges 
between  the  sacram  and  coccyx,  and  supplies  the  multifidus 
spinaB  muscle  and  the  skin  of  the  posterior  gluteal  region  ;  a 
branch  goes  from  the  third  and  fourth  nerves  to  the  bladder ; 
the  two  lower  nerves  join  with  the  coccygeal,  forming  loops, 
which  supply  the  skin  over  the  coccygeal  region  and  the  coccy- 
geus,  levator  ani,  and  sphincter  ani  muscles. 

The  Sympathetic  System. 

What  is  the  sympathetic  nerye  or  system? 

It  consists  of  (1)  a  series  of  ganglia  with  intervening  longi- 
tudinal bands,  forming  two  cords,  ono  on  each  side  of  the  spinal 
column  connected  above  according  to  some  by  the  ganglion  of 
RiheSj  and  below  by  the  ganglion  impar  or  coccygeal  ganglion, 
in  front  of  the  coccyx  ;  (2)  three  prevertebral  plexuses,  one 
each  for  the  thorax,  abdomen,  and  pelvis;  (3)  small  ganglia; 
(4)  nerve-fibers  of  communication  with  the  cerebro-spinal 
nerves,  of  distribution  supplying  the  viscera  and  vessels. 

Describe  the  cervical  ganglia. 

There  are  three  on  either  side,  viz.  the 

Superior  cervical  ganglion.  It  is  placed  opposite  the  second 
and  third  cervical  vertebrae  behind  the  carotid  sheath,  and 
gives  off  a 

Superior  branch  to  the  internal  carotid  artery,  forming  by 
its  division  the  cavernous  plexus  and  carotid  plexus  (with 
their  subdivisions)  ; 

Descending  branch,  connecting  the  superior  with  the  middle 
ganglion  ; 

External  branches  to  the  cranial  and  spinal  nerves,  and  an- 
terior branches  forming  plexuses  on  the  external  carotid  and  its 
branches ; 

Pharyngeal,  forming  with  branches  from  the  spinal  acces- 
sory, pneumogastric,  glosso-pharyngeal,  and  external  laryn- 
geal nerves,  the  pArn^/^^ec//  p/f'x^^s ;  laryngeal,  uniting  with 
the  superior  laryngeal   nerve  and  its  branches  ; 

Superior  cardiac,  connected  with  other  branches  of  the  sym- 


THE  SYMPATHETIC  SYSTEM.  257 

pathetic,  and  with  some  of  the  pneumogastrie,  passes  to  the 
back  of  the  aorta,  the  right  joining  the  deep,  and  the  left 
(usually)   the  superjicidl  cardiac  plexus. 

Middle  cervical  ganglion  is  placed  opposite  the  sixth  cervical 
vertebra  ;  and  by  its 

Superior  and  inferior  branches  it  communicates  respectively 
with  the  superior  and  the  inferior  cervical  ganglia  ;  the  exter- 
nal filaments  join  the  fifth  and  sixth  cervical  nerves,  the  internal 
are  the  thyroid  to  the  inferior  thyroid  artery  and  thyroid  gland, 
and  the  middle  or  great  cardiac  nerve,  communicating  with  other 
sympathetic  branches  and  the  recurrent  laryngeal,  to  terminate 
in  the  deep  cardiac  plexus. 

Inferior  cerviccd  ganglion  is  placed  between  the  base  of  the 
transverse  process  of  the  seventh  cervical  vertebra  and  neck 
of  the  first  rib  on  the  inner  side  of  the  superior  intercostal 
artery ;  its  superior  and  inferior  branches  connect  it  respectively 
with  the  middle  cervical  and  the  first  thoracic  ganglion  ;  the 
external  branches  join  the  spinal  nerves,  others  form  a  plexus 
on  the  vertebral  artery  ;  its  chief  branch  is  the 

Inferior  cardiac  nerve,  communicating  with  the  recurrent 
laryngeal  and  middle  cardiac  nerves,  terminating  in  the  deep 
cardiac  plexus. 

What  is  the  carotid  plexus? 

It  is  a  plexus  situated  on  the  outer  side  of  the  internal  caro- 
tid artery  communicating  with  the  Gasserian  and  spheno-pala- 
tine  ganglia,  the  sixth  nerve,  and  the  tympanic  branch  of  the 
glosso-pharyngeal ;  it  supplies  the  carotid  artery  and  dura  mater. 

What  is  the  cavernous  plexus? 

It  is  one  situated  below  and  internal  to  that  part  of  the  in- 
ternal carotid  artery  running  alongside  of  the  sella  turcica,  in 
the  cavernous  sinus;  it  communicates  with  the  third,  fourth, 
fifth,  and  sixth  nerves,  and  ophthalmic  ganglion,  and  supplying 
the  carotid,  it,  with  the  carotid  plexus,  forms  plexuses  embrac- 
ing the  cerebral  and  ophthalmic  arteries. 

What  are  the  other  ganglia  of  the  sympathetic  system? 

I'sually   cluvun   thoracic,  four   lumbar,   four  or   five   sacral, 
ganglion    impar,   and   numerous   ganglia    connected   with    the 
various  viscera,  whence!  ])lexuses  are  formed  named  from  their 
locality  or  the  organ  involved. 
17 


258  ESSE>'TIALS  OF  HUMAN    ANATOMY. 

What  are  the  branches  of  the  thoracic  portion  ? 

Contiiuniicafiiif/.  witli  one  uiiutlier  luid  the  thoracic  spinal 
nerves,  fihinients  to  the  aorta  aud  its  divisions  and  to  the  pos- 
terior pulmonary  plexus,  and 

The  (/rrdf  uphincJuiic  nerve,  formed  by  the  internal  branches 
from  the  thoracic  ganglia  between  the  fifth  or  sixth  and  ninth  or 
tenth  inclusive  :  it  perforates  the  crus  of  the  diaphragm  to  ter- 
minate in  the  semilunar  ganglion,  sending  branches  to  the  renal 
plexus  and  suprarenal  capsule. 

The  snidU  aphi aclinic,  springing  from  the  ninth  and  tenth, 
or  from  the  tenth  and  eleventh  ganglia  and  cord  communicat- 
ing with  the  great  splanchnic,  pierces  the  diaphragm  with  the 
preceding,  to  join  the  celiac  plexus. 

Smalksf,  or  renal  splanc/uu'c,  arises  from  the  last  ganglion, 
occasionally  communicates  with  the  preceding,  pierces  the  dia- 
phragm, and  terminates  in  the  renal  aud  lower  part  of  the 
celiac  plexus. 

Describe  the  solar  plexus. 

It  supplies  all  the  abdominal  viscera,  consisting  of  a  network 
of  nerves  and  ganglia  lying  in  front  of  the  aorta  and  crura  of 
the  diaphragm,  surrounding  the  celiac  axis  and  root  of  the 
superior  mesenteric  artery,  extending  below  to  the  pancreas, 
and  laterally  to  the  suprarenal  capsules.  The  great  splanchnic 
and  part  of  the  small  splanchnic  nerves  of  both  sides  and  the 
termination  of  the  right  pneumogastric  form  this  plexus,  in 
conjunction  with  the  two  semilunar  ganglia,  these  latter  being 
large,  irregular  gangliform  masses,  composed  of  smaller  ganglia 
separated  by  interspaces,  placed  by  the  side  of  the  celiac  axis 
and  superior  mesenteric  artery,  close  to  the  suprarenal  capsules, 
that  on  the  right  lying  beneath  the  vena  cava.  From  this  are 
derived  the  following  plexuses  accompanying  the  same  named 
arteries  to  the  various  organs : 

Phrenic,  or  diaphragmcitic,  Sujyi-arenul, 

C  Gastric,  Renal, 

Celiac  <  Hepatic,  Superior  inesentericy 

(^  Splenic,  Spermatic, 

Aortic,  Inferior  mesenteric. 

Name  some  of  the  more  important  plexuses. 
Tymjninic  (see  page  370). 
Great,  or  deep  cardiac  is  placed   in  front  of  the  bifurcation 


THE   DIGESTIVE  ORGANS.  259 

of  the  trachea,  and  above  that  of  the  pulmonary  artery,  be- 
hind the  aortic  arch,  and  is  formed  by  all  the  sympathetic  car- 
diac nerves  (except  the  left  superior)  and  cardiac  branches  of 
the  recurrent  laryngeal  and  pneumogastric  (except  the  left  supe- 
rior cardiac  and  the  left  inferior  cardiac  of  the  pneumogastric). 

SuperJiciaJ  cardiac  lies  beneath  the  aortic  arch  in  front  of 
the  right  pulmonary  artery,  and  is  formed  by  the  left  superior 
cardiac  of  the  sympathetic,  left  inferior  cardiac  of  the  pneumo- 
gastric, and  branches  from  the  deep  cardiac  plexus. 

Coronary^  the  posterior^  chiefly  from  the  deep,  the  anterior 
from  the  superficial  cardiac  plexus. 

Aortic^  on  the  sides  and  front  of  the  aorta  between  the 
origins  of  the  superior  and  inferior  mesenteric  arteries. 

Hypogastric,  lying  in  front  of  the  sacrum,  between  the  com- 
mon iliac  arteries,  supplies  the  pelvic  viscera,  and  is  formed  by 
filaments  from  the  aortic  plexus,  and  from  the  lumbar  and  first 
two  sacral  ganglia,  contains  no  ganglia,  and  divides  into  two 
lateral  portions,  forming  the  inferior  hypogastric  or  pelvic 
plexuses. 

Pelvic  plexnms.  two  in  number,  lie  upon  each  side  of  the 
rectum  and  bladder  (rectum,  vagina,  and  bladder  in  females;, 
and  each  is  formed  by  a  continuation  of  the  hypogastric  plexus 
and  branches  from  the  second,  third,  and  fourth  sacral  nerves, 
and  a  few  filaments  from  the  sacral  ganglia ;  the  branches 
accompany  those  of  the  internal  iliac  artery,  and  are  distributed 
to  all  the  pelvic  viscera ;  their  branches  are  : 

Inferior  hemorrhoidal  plexus^ 

Vesical  plex us,  Vaginal  plexus, 

C  Small  and  large 
Prostatic  plexus     I  cavernous  nerves  Uterine  nerves. 

(^        to  penis. 

VISCERAL   ANATOMY. 

The  Digestive  Organs. 

What  is  a  viscus? 

Any  of  the  internal  organs  with  their  appendages,  contained 
within  the  four  cavities,  cranial,  thoracic,  abdominal,  or  pelvic. 

Of  what  does  the  digestive  apparatus  consist  ? 

or  the  alimentary  canal,  a  musculo-membranous  tube,  lined 


260 


ESSENTIALS  OF  HUMAN   ANATOMY. 


with  mucous  membrane,  a])out  thirty  feet  long,  extending  from 
the  mouth  to  the  anus,  and  certain  accessory  organs. 

Name  the  subdivisions  of  the  alimentary  canal. 

Mouth,  pharynx,  esophagus,  stomacli,  small  intestine  (duo- 
denum, jejunum,  ileum),  large  intestine  (cecum,  colon,  sig- 
moid flexure,  rectum). 

What  are  the  accessory  organs? 

The  teeth,  salivary  glands  (parotid,  submaxillary,  sublin- 
gual), liver,  pancreas,  and  spleen. 


The  Teeth. 

What  is  their  function? 

To  reduce  the  food  to  fragments,  thus  enabling  the  digestive 
fluids  to  act  to  the  best  advantage.     There  are  two  classes : 

Temporary^  or  milk  teefli^  ten  in  each  jaw,  viz.  four  incisors, 
two  canines,  and  four  molars ; 

Permanent  teeth^  sixteen  in  each  jaw,  viz.  four  incisors,  two 
canines,  four  bicuspids  or  premolars,  and  six  molars. 

The  surface  of  a  tooth  turned  toward  the  lips  or  cheeks  is 
called  lahial^  or  buccal;  toward  the  tongue  is  Ungnal ;  toward 

the  mesial  line  is  proximal ;  and  away 
from  it  is  distal. 


Of  what  parts  does  every  tooth  consist  ? 

Of  a  crojcn,  or  hocli/  (Fig.  113),  that 
part  projecting  above  the  gum. 

JVeck,  the  constricted  portion  between 
the  crown  and  the  fang. 

Fang^,  or  root.,  that  part  occupying  the 
alveolus,  held  there  by  the  dental  perios- 
teum lining  the  socket  and  investing  the 
fang ;  teeth  are  steadied  by  the  gums, 
composed  of  dense  fibrous  tissue  covered 
with  mucous  membrane. 

Pulp-cavity'^.,  an  interior  cavity  filled 
with  the  tooth-pulp,  a  vascular  connec- 
tive tissue  with  numerous  nerves,  both 
arteries  and  nerves  reaching  the  pulp  by 
a  canal  opening  at  the  apex  of  the  fang. 


Fig.    113.— Vertical    sec- 
tion of  a  molar  tooth. 
(Leidy.) 


THE  TEETH.  261 

Describe  the  characteristics  of  each  of  the  four  varieties  of 
teeth. 

Incisor,  or  cutting  teeth.  The  crown  is  wedge-shaped,  convex 
111  front,  bevelled  and  slightly  concave  behind ;  the  fang  is 
single,  long,  conical,  and  transversely  flattened ;  the  lingual 
surface  shows  a  hasal  ridge,  or  cingulum. 

Canines.  Crown  is  large,  conical,  convex  in  front,  rises 
above  the  level  of  the  other  teeth  ;  fang  long,  conical,  com- 
pressed laterally  ;  upper  pair  are  called  in  common  parlance 
eye-teeth,"  the  lower  "  stomach-teeth." 

Bicuspids.  Crown  has  two  projecting  cusps,  fang  generally 
is  single,  laterally  grooved  with  a  bifid  apex  ;  they  are  also 
called  premolars;  the  upper  are  larger  than  the  lower. 

Molars  (grinders).  Crown  nearly  cubical,  with  four  cusps 
in  the  upper,  and  five  in  the  lower  molars  ;  fangs,  usually  three 
for  the  first  two  upper,  and  two  for  the  first  two  lower  molars; 
the  third  molar  is  called  the  ''  wisdom  tooth  "  (dens  sajnenfise), 
from  its  late  appearance,  and  usually  has  but  one  fang  with 
grooves  indicating  a  tendency  to  the  formation  of  three  fangs 
in  the  upper,  and  two  in  the  lower  jaw. 

The  second  temprjrary  molar  is  the  largest  milk  tooth,  and  is 
succeeded  by  the  second  permanent  bicuspid. 

Describe  the  structure  of  a  tooth. 

Each  is  formed  chiefly  of 

Dentine,  or  ivory'^,  composed  of  minute,  wavy,  branching 
tubes,  called  dentinal  tuhes,  embedded  in  a  hard,  homogeneous 
tissue,  the  intertuhular  suhstance.  The  tubules  are  about  4-5^00" 
of  an  inch  in  diameter,  dividing  dichotomou.sly,  giving  the 
wavy  appearance  of  the  cut  surface,  and  open  into  the  pulp- 
cavity.  Chemically  dentine  consists  of  twenty-eight  parts  of 
animal  and  seventy-two  of  earthy  matter. 

EnameP  forms  a  thin  crust  over  the  crown,  is  the  densest  of 
all  animal  tissues,  containing  only  3.5  per  cent,  of  animal  mat- 
ter, and  is  composed  of  minute  parallel  hexagonal  rods,  or 
enanu'l  columns,  about  -^-V^  of  an  inch  in  diameter,  pursuing 
a  wavy  course. 

Cement,  or  crusfa  petrosa*,  is  a  layer  of  true  bone  commenc- 
ing at  the  neck,  covering  the  fang,  and  becoming  thicker  to- 
ward its  apex. 

Pulp,  filling  the  pulp-cavity',  consisting  of  soft,  very  vascu- 


262 


ESSENTIALS  OF  HUMAN  ANATOMY. 


lar  connective  tissue,  with  numerous  nerves  and  cells,  the  lat- 
ter being  of  two  kinds,  columnar,  called  odontohlnsts — arranged 
in  a  layer  lining  the  pulp-cavity — some  stellate  and  fusiform 
cells  wedged  in  between  these  permeate  the  pulp,  having  fine 
processes,  prolonged  into  the  dentinal  tubules ;  certain  fila- 
ments in  the  tubules  are  Tomes  filers. 

Whence  do  teeth  obtain  their  blood-  and  nerve-supply? 

From  the  alveolar  and  infraorbital  branches  of  the  internal 
maxillary,  and  from  the  inferior  dental  artery  ;  the  nerves 
come  from  the  anterior  and  posterior  dental  branches  of  the 
superior  maxillary,  and  from  the  inferior  maxillary  division  of 
the  fifth  nerve. 

When  do  the  temporary  teeth  appear? 

The  time  is  variable,  but,  according  to  the  latest  authority, 
they  erupt  as  follows,  expressed  in  months : 


a5 

u 

C 

u 

C 

OJ 

u 

tH 

C3 

o 

o 

o 

o 

C 

fH 

u 

e3 

OS 

m 

x 

ai 

m 

(A 

03 

C 

o 

C 

O 

o 

O 

'S 

S 

o 

o 

S 

g 

o 

1— 1 

B 
8-10 

1^ 

fl 
^ 

6 

% 

§ 

Upper 

20-24 

15-21 

16-20 

8-10 

8-10 

8-10 

16-20 

15-21 

20-24 

Lower 

20-24 

15-21 

16-20 

15-21 

6-9 

6-9 

15-21 

16-20 

15-21 

20-24 

The  order  of  their  appearance  is,  first,  the  lower  central  in- 
cisors ;  then  the  upper  central  incisors,  closely  followed  b}"  the 
laterals  ;  then  the  lower  laterals  ;  next  the  upper  anterior  mo- 
lars followed  by  the  lower ;  then  the  upper  canines  followed  by 
the  lower;  finally,  the  lower  back  molars,  followed  by  the 
upper. 

Describe  the  order  of  appearance  of  the  permanent  teeth. 

The  first  to  appear  are  the  first  molars  at  the  end  of  the  sixth 
year,  the  lower  teeth  usually  preceding  the  upper ;  thus,  ex- 
pressed in  years.,  these  teeth  erupt  as  follows : 


a 

o 

'CS 

'6 

-d 

i 

13 

iL 

0) 

(- 

X 

0^ 

^ 

X 

p. 

CO 

-7^ 

o 

s 

c; 

"S 

O 

c 

(3 

O 

o 

"r 

O 

Oi 

% 

§ 

7 

11 

PQ 

6 

1— 1 

5 

t— 1 

6 

10 

PQ 
11 

'^ 

S 

^ 

Upper  . 

18-30 

13-16 

10 

11-13 

9 

8 

8 

9 

11-13 

7 

13-16 

18-30 

Lower  . 

17-25 

12-13 

6 

10 

9 

11-12 

8 

7 

7 

8 

11-12 

9 

10 

6 

12-13 

17-25 

THE  MOUTH.  263 

Describe  the  development  of  the  teeth. 

The  enamel  is  derived  from  the  ectoderm  ;  the  dentin,  ce- 
mentum.  and  pulp  from  the  mesoderm.  A  lineur  tliickf^nuig  of 
oral  epithelium  appears  before  the  sixth  week  ;  next  follows  a 
lateral  (labial)  projection,  the  dental  ridge.,  growing  into  the 
mesoderm,  forming  a  furrow  on  the  oral  surface,  the  dental 
groove  of  Goodsir.  The  positions  of  the  future  teeth  are 
marked  by  local  thickenings  under  the  ridge,  the  dental  bidbs, 
which  become  the  enamel  organs  of  the  temporary  teeth  ;  the 
dental  ridge  atrophies  ;  these  primitive  enamel  organs  become 
invaginated  like  an  epithelial  cap  over  a  mesodermic  dental 
jjajidl'i^  embracing  about  two-thirds  of  it ;  the  cap  shows  three 
layers — the  external,  of  one  or  two  rows  of  low  columnar  cells, 
the  outer  enamel  cells;  they  are  reflected  to  form  the  inner  in- 
vaginated layer  of  the  organ,  the  inner  enamel  cells.  These  two 
layers  are  separated  at  first  by  a  middle  layer,  which  undergoes 
great  changes :  a  network  is  formed,  reduced  to  thin  plates, 
fluid  collects  (enamel  j^'dp),  and  finally  all  disappears.  At  the 
sides  of  the  primitive  organs  the  second  enamel  organ  develops 
the  permanent  teeth.  The  inner  layer  above  produces  enamel, 
enamel  membrane.  The  top  and  sides  of  the  dental  papillae  are 
covered  -by  odontoblasts,  whose  processes  are  dentinal  fibers  ; 
the  canals  left  are  dentinal  tubules,  homologues  of  the  canaliculi 
of  bone.  The  central  part  of  a  dental  papilla  remains  as  pnlp- 
tissue.  The  cementnm  is  formed  last  of  all  from  an  epithelial 
sheath,  but  not  in  fetal  life,  and  increases  to  old  age.  By  the 
gradual  growth  of  the  fang  the  crown  produces  absorption  by 
pressure  upon  the  overlying  bone  and  mucous  membrane,  when 
eruption  occurs. 

The  Mouth. 
What  is  the  mouth? 

It  is  an  ovoid  cavity  in  which  food  is  masticated,  bounded 
by  the  lips  in  front,  by  the  cheeks  and  alveolar  processes  of 
both  jaws  with  their  contained  teeth  at  the  sides,  by  the  hard 
palate  above,  by  the  tongue  and  floor  of  the  mouth  below,  and 
behind  by  the  soft  palate  and  the  anterior  pillars  of  the  fauces 
where  it  opens  into  the  pharynx  ;  it  is  lined  by  mucous  mem- 
brane covered  by  scaly  stratified  epithelium  containing  numer- 
ous racemose  glands,  continuous  with  the  skin  at  the  free  mar- 
gin of  the  lips;  it  presents  for  examination 

The  hard  palate^  formed  by  the  palatal  processes  of  the  supe- 


264  ESSENTIALS  OF  HUMAN   ANATOMY. 

rior  maxillary  and  palate  bones  covered  by  the  intimately 
adherent  periosteum  and  mucous  membrane  furnished  with 
palatal  glands. 

The  8oft  palate,  consisting  of  a  fold  of  mucous  membrane 
depending  from  the  posterior  border  of  the  hard  palate,  en- 
closing muscular  tissue,  an  aponeurosis,  adenoid  tissue,  mucous 
glands,  etc. ;  the  muscles  on  each  side  are  five,  the  levator  and 
tensor  palati.  palato-glossus,  palato-pharyngeus,  and  azygos 
uvulffi — the  latter  with  its  fellow  forming  the  median  pro- 
jecting conical   uvula. 

Anterior  and  posterior  jnllars  of  the  fauces.,  the  former  con- 
taining within  a  fold  of  mucous  membrane  the  palato-glossus 
muscle  on  each  side,  arching  downward  and  forward  from  the 
palate  to  the  base  of  the  tongue  ;  the  latter,  the  palato-pharyn- 
gei  muscles,  passing  backward  and  downward  to  the  sides  of 
the  pharynx. 

Isthmus  fauciuui  is  the  space  bounded  by  the  pillars  of  the 
fauces  and  tonsils,  base  of  the  tongue,  and  free  margin  of  the 
soft  palate. 

Tonsils'  (Fig.  114).  situated  between  the  anterior  and  the 
posterior  pillars  on  each  side,  consisting  of  glandular  tissue 
containing  twelve  to  fifteen  openings  leading  into  crypts  lined 
with  mucous  membrane,  external  to  which  is  a  layer  of  closed 
capsules  analogous  to  those  of  Peyer's  glands  ;  the  tonsil  is 
only  separated  from  the  internal  carotid  artery  by  the  superior 
constrictor  muscle. 

Openings  of  the  ducts  rf  Stensen.  opposite  the  second  upper 
molar  tooth  on  each  side,  delivering  the  secretion  of  the  parotid 
glands. 

Openings  of  the  ducts  of  Wharton,  one  on  either  side  of  the 
frenum  of  the  tongue,  delivering  the  secretion  of  the  submax- 
illary glands. 

Openings  of  the  ducts  of  the  suhlingiial  gland  {ducts  of  Ri  duns'), 
from  eight  to  twenty  in  number ;  they  open  on  an  elevated 
crest  of  the  mucous  membrane  on  each  side  of  the  frenum 
linguae,  one  or  more  joining  in  a  tube  opening  into  Wharton's 
duct  called  the  dnct  of  Bartholin. 

What  are  the  salivary  glands? 

Three  compound  racemose  glands  on  each  side.  The  parotid, 
the  largest,  lies  below  and  in  front  of  the  ear  between  the 


THE  MOUTH. 


265 


zygoma  above,  mastoid  behind,  and  ramus  of  the  jaw  in  front 
— its  duct  is  Stenseiis;  the  submaxt'llari/ Vies  below  the  jaw 
in  the  anterior  part  of  the  submaxilhiry  triangle — its  duct  is 
Wharton's  ;  the  siihlingiud  lies  beneath  the  mucous  membrane 
of  the  floor  of  the  mouth  against  the  jaw,  close  to  the  sym- 
physis— its  ducts  are  those  of  Rivinns. 

Describe  the  tongue. 

Its  base  is  attached  to  the  hyoid  bone  and  lower  jaw  by 
muscles,  to  the   epiglottis   by   two   lateral   and   one  median^ 


Fk;.  111.— Dorsum  of  the  tongue  (Lcidy). 


266  ESSENTIALS  OF  HUMAN  ANATOMY. 

glosso-epiglottic  folds  of  mucous  membrane,  and  to  the  soft 
palate  by  the  anterior  pillars;  its  tip,  sides,  dorsum,  and  part 
of  the  under  surface  are  free ;  a  median  raphe  and  fibrous 
septum  divide  the  organ  into  halves  ;  its  mucous  membrane 
reflected  over  the  floor  of  the  mouth  to  the  gums  forms  in 
front  an  antero-posterior  fold,  the  freiiinn  lingua  ;  the  tongue 
is  formed  by  certain  intrinsic  muscular  fibers,  viz.  those  of  the 
lingualis,  and  by  extrinsic  muscles,  the  stylo-glossus,  hyo- 
glossus,  genio-hyo-glossus,  and  palato-glossus  (see  p.  148). 
The  mucous  membrane  of  the  tongue  presents  the 

CircumvaUdte  papillae,  numbering  eight  to  ten,  arranged  on 
the  back  part  of  the  dorsum  in  two  lines  converging  behind 
like  a  letter  V ;  just  behind  the  junction  is  a  little  recess,  the 
foramen  csecum'\  prolonged  in  the  fetus  by  the  tliyro-glossal 
duct  to  the  pyramidal  process  of  the  thyroid  gland. 

Fungiform  papillae^,  scattered  over  the  dorsum,  but  chiefly 
found  at  the  sides  and  apex. 

Filiform  or  conical  papillse,  *,  with  secondary  papillae  project- 
ing from  their  apices,  arranged  in  lines  cover  the  anterior  two- 
thirds  of  the  dorsum  of  the  tongue. 

Racemose  lingual  glands'^,  situated  along  the  sides,  but 
chiefly  over  the  posterior  third  of  the  dorsum  ;  some  secrete 
mucus,  others  serum. 

Lymphoid  tissue,  collected  into  masses  or  folliclfs,  exhibits 
crypts ;  one  collection  far  back  is  called  the  lingual  tonsil. 

Name  the  blood-supply. 
This  is  from  the  : 

r  Dorsalis  linguse,     Facial,    by    the    submental 
Lingual  <  Suhlingual,  branch   anastomosing  with 

(^  Ranine,  the  sublingual. 

Ascending  pharyngeal, 

Describe  the  nerve-supply. 

The  lingual  branch  of  the  fifth  is  distributed  to  the  papillse 
at  the  front  and  sides  to  the  extent  of  two-thirds  of  its  surface, 
endowing  these  parts  with  general  sensation ;  the  chorda 
tymj)ani  has  the  same  distribution,  and  seems  to  be  the  nerve 
of  taste  to  this  region. 

Lingufd  branch  of  the  glosso-pharyngeal ,  supplying  the 
mucous  membrane  of   the  base  and  sides    and  circumvallate 


THE  PHARYNX.  267 

papilhTS  or  posterior  third ;  it  is  the  nerve  of  taste  and  sensa- 
tion for  these  parts. 

Hypoglossal^  to  the  muscles  ;  tlie  motor  nerve. 

Superior  laryngeal  sends  a  few  filaments  to  the  base  near  the 
epiglottis  from  its  internal  branch  ;  thus,  five  nerves  supply 
each  side. 

What  anatomical  points  of  surgical  interest  does  the  palate 
present  in  the  vicinity  of  the  last  molar  tooth  ? 
Just  behind  this  tooth  the  liamular  process  and  the  mfernal 
pterygoid  plate  can  be  felt,  the  point  for  division  of  the  tensor 
palati  aponeurosis  in  the  operation  for  cleft  palate ;  and  in  front 
of  this  to  the  inner  side  of  the  last  molar  tooth  is  the  posterior 
jKilatine  artery  as  it  emerges  from  the  canal,  sometimes  re- 
quiring plugging  after  a  cleft-palate  operation  ;  in  resection  of 
the  inferior  dental  nerve,  locate  the  last  molar  tooth,  enter  the 
mucous  membrane  and  find  the  lingula  on  the  ramus  of  the 
jaw  which  is  just  above  and  anterior  to  the  nerve. 

The  Pharynx. 

What  is  the  pharynx  ? 

A  conical  musculo-membranous  sac,  about  five  inches  long, 
extending  from  the  under  surface  of  the  base  of  the  skull  to  a 
point  corresponding  to  the  cricoid  cartilage  or  sixth  cervical 
vertebra.  It  is  widest  opposite  the  aperture  of  the  larynx, 
narrowest  below,  where  it  terminates  in  the  esophagus ;  it  is 
bounded  ahove  by  the  basilar  process  and  body  of  "the  sphe- 
noid; is  connected  posteriorly  with  the  cervical  vertebrae, 
longus  colli  and  recti  capitis  antici  muscles  ;  anteriorly  it  is 
incomplete,  opening  into  the  mouth,  being  attached  to  the 
internal  pterygoid  process,  pterygo-maxillary  ligament,  lower 
jaw,  tongue,  hyoid  bone  and  larynx  ;  since  it  lies  behind  the 
nose,  mouth,  and  larynx,  it  should  be  described  in  three  parts 
— nasal,  oral,  laryngeal;  laterally,  it  is  attached  to  the  styloid 
processes  and  muscles  arising  from  them,  while  the  common 
and  internal  carotid  arteries,  the  intermil  jugular  veins,  ninth, 
tenth,  twelfth,  and  syni])athetic  nerves  hen;  lie  in  contact  with 
it.  The  cavity  \\^i!>  seven  openings:  the  two  posterior  nares, 
two  Eustachian  tubes,  mouth,  larynx,  and  esophagus.  A  con- 
sider;ibl<;  mass  of  lymphoid  tissue  extends  across  tlie  back  of 
the  pharynx,  between  the  orific<!S  of   the   Eustachian    tubes, 


268 


ESSENTIALS  OF   PIUMAN   ANATOMY. 


called  the  jiharyngeal  tonsil ;  a  recess  in  the  mucous  membrane 
always  exists  in  the  fetus,  the  j>h(in/ii(jr(il  hnrsfi.  which  passes 
u}»  tu  the  pharyngeal  spine  ;  behind  the  opening  of  the  Eusta- 
chian tube  is  the  fossa  of  Rosenmiiller ;  from  the  end  of  the 
tube  descends  a  salpingo-plKivijiif/rdl  fold  of  mucous  mem- 
brane, covering  in   the  salpingo-pltaryiigeus  muscle. 

Of  how  many  coats  does  it  consist  ? 

Three :  an  internal  mucous,  continuous  with  that  lining:  the 
mouth,  etc.,  covered  with  ciliated  epithelium  down  to  the  level 
of  the  floor  of  the  nares,  below  by  squamous  epithelium,  con- 
taining racemose  glands  most  plentiful  around  the  orifices  of 
the  Eustachian  tubes,  and  much  lymphoid  tissue  surrounding 
crypts,  called  the  tubal  tonsils ;  a  middle  fibrous  coat  (^pharyn- 
geal ffjioneiirosis),  thick  above,  where  the  muscular  fibers  are 
wanting;  and  an  external  muscular  coat  composed  of  the  supe- 
rior, middle,  and  inferior  constrictors,  stylo-pharyngeus.  palato- 
pharyngeus.  and  salpingo-pharyngeus  muscles. 

Describe  the  pharyngeal  muscles    Fig.  115). 

Inferior  constrictor*^:  origin,  side  of  the  cricoid  and  thyroid 

cartilages;   //z>v//'/o/^  unites  with  its  fellow;  action,  constricts 

the  pharynx  during  swallowing ; 
nerves,  pharyngeal  plexus,  from 
glosso-pharyngeal.  external  laryngeal, 
recurrent  laryngeal,  spinal  accessory. 

Middle  constrictor":  origin,  greater 
and  lesser  cornua  of  the  hyoid  bone 
and  stylo-hyoid  ligament ;  insertion, 
unites  with  its  fellow ;  action,  same 
as  above ;  nerves,  glosso-pharyngeal, 
spinal  accessory  through  the  pharyn- 
geal plexus. 

Superior  constrictor  ^"^ :  origin,  lower 
third  of  the  margin  of  the  internal 
pterygoid  plate  and  hamular  process, 
contiguous  surface  of  the  palate  bone^ 
reflected  tendon  of  the  tensor  palati 
muscle,  pterygo-maxillary  ligament, 
alveolar  process  above  the  posterior 
end  of  the  mylo-hyoid  ridge  and  side 

of  the  tongue;   insertion,  posterior  median  raphe  and  pharyn- 


FiG.     llo.— Muscles    of    the 
pharynx,  posterior  view. 


THE  ESOPHAGUS.  269 

geal  spine  of  the  occipital  bone;  action,  same  as  the  other 
constrictors;  nerve,  spinal  accessory  through  the  pharyngeal 
plexus. 

Stylo-pharyngeus *^ :  (jvlglii,  inner  side  of  the  base  of  the  sty- 
loid process;  insertion,  blends  with  the  constrictor  muscles, 
and  is  also  inserted  into  the  posterior  border  of  the  thyroid 
cartilage;  action,  draws  the  sides  of  the  pharynx  upward  and 
outward ;  nerve,  glosso-pharyngeal. 

What  arteries  supply  the  pharynx? 

Superior  tlujroid,  Tonsillar, 

Ascending  pharyngeal,  Ptery go-palatine,  ^ 

Ascending  pjalatine,  Descending  palatine. 

What  are  its  nerves? 

Branches  from  the  pharyngeal  plexus,  formed  by  the  phar- 
yngeal branches  of  the  glosso-pharyngeal,  pneumogastric,  ex- 
ternal laryngeal,  all  derived  from  the  spinal  accessory  and 
sympathetic  nerves. 

The  Esophagus. 

Describe  it  with  coats,  vessels,  and  nerves. 

It  is  a  muscular  canal,  nine  or  ten  inches  long  (23-26  cm.), 
joining  the  pharynx  and  stomach,  commencing  at  the  lower 
border  of  the  cricoid  cartilage,  passing  through  the  esophageal 
opening  of  the  diaphragm,  to  terminate  at  the  cardiac  orifice 
of  the  stomach,  opposite  the  eleventh  thoracic  vertebra;  it  has 
three  parts  :  the  cervical,  to  the  opening  of  the  thorax  ;  the  thor- 
acic, from  the  second  thoracic  vertebra  to  the  tenth  ;  the  ahdom- 
inal,  about  one  inch  long  below  the  diaphragm  ;  it  has  three 
curves,  one  antero-posterior  and  two  lateral ;  in  the  neck  it  lies 
between  the  trachea  and  the  spinal  column  and  longus  colli 
muscle,  at  the  lower  part  inclining  to  the  left,  having  on  either 
side  the  common  carotid  artery,  with  the  lateral  lobes  of  the 
thyroid  gland — the  recurrent  laryngeal  nerves  ascend  between  it 
and  the  trachea  ;  in  the  thorax,  after  passing  behind  the  aortic 
arch,  it  runs  to  the  right  of  the  vessel,  to  pass  in  front  and  to 
the  left  again  before  piercing  tlie  diapliragm. 

It  has  three  coats  :  internal  mucous,  when  empty  thrown  into 
longitudinal  folds,  containing  numerous  glands,  its  surface  being 


270  ESSENTIALS  OF  HUMAN  ANATOMY. 

studded  with  small  papilla),  and  covered  by  squamous  epithe- 
lium ;  at  its  lower  end  the  next  coat  is  the  niuscalarts  mucome  ; 
a  middle  areolar  coat  loosely  connects  the  mucous  and  the 
succeeding  coat;  a  niuscnhir,  composiid  of  an  external  longi- 
tudinal and  internal  circular  layer,  the  fibers  ahoce  consisting 
chiefly  of  the  striated,  but  below  almost  entirely  of  the  unstriped 
involuntary  variety. 

The  arteries  are  from  the  inferior  th^Toid,  thoracic  aorta,  left 
inferior  phrenic,  and  coronary  of  the  stomach ;  they  have  a 
ongitudinal  direction. 

The  veuLS  empty  into  the  inferior  thyroid,  azygos  minor,  and 
coronary  of  the  stomach ;  the  portal  and  the  general  system 
meet  on  the  esophagus. 

The  nerves  are  from  the  esophageal  plexus,  formed  by  the 
pneumogastric  and  recurrent  laryngeals,  with  some  sympathetic 
filaments. 

The  Stomach. 

Describe  it. 

The  stomach  is  a  pear-shaped  dilatation  of  the  alimentary 
canal  connecting  the  esophagus  with  the  small  intestine.  Its 
larger  end  points  above  and  to  the  left ;  its  smaller,  below  and 
to  the  right.  The  mouth  of  the  stomach  receiving  the  esopha- 
gus is  called  the  eardia.  To  the  left  and  below  this  is  the 
fundus,  forming  about  one-fifth  of  the  stomach  ;  this  continues 
on  the  right  into  the  hod?/  of  the  stomach,  which  has  two  sur- 
faces included  between  two  borders ;  the  anterior  surface  looks 
upward  and  forward,  the  posterior,  downward  and  backward ; 
the  lesser  curvature  is  concave  above  and  to  the  right,  and  is 
attached  to  the  liver  by  the  lesser  omentum  ;  the  greater  curva- 
ture is  convex,  turned  to  the  left  and  downward,  and  gives 
attachment  to  the  great  omentum.  At  the  right  and  lower 
end  of  the  stomach  the  body  contracts  into  the  pyloric  jwrtion, 
which  presents  two  or  three  bulging  parts,  each  one  called  the 
pyloric  antrum  ;  these  pouches  are  caused  by  the  ^\iori  pyloric 
ligaments.  The  external  constriction  between  the  stomach  and 
the  duodenum  is  the  pyloric  sulcus,  made  by  a  muscular  ring,  the 
pyloric  sphincter  ;  an  internal  projection  of  the  mucous  mem- 
brane is  produced,  called  the  pyloric  Vfdve  or  pylorus.  The 
peritoneum  related  consists  of  the  lesser,  great,  and  gastro- 
splenic  omenta,  and  a  gastro-phrenic  ligament. 


THE  STOMACH.  271 

Dimensions  and  Position. — Length,  ten  to  twelve  inches ; 
vertical  diameter,  four  to  five  inches  ;  antero-posterior,  three 
and  one-half  inches  ;  distance  between  the  two  orifices,  three 
to  six  inches.  ]juschka's  measurements  of  the  same  lines  are  : 
3-t  cm.,  15  cm.,  3.7  to  11.5  cm.  Weight  is  four  and  one-half 
ounces ;  capacity,  five  to  eight  pints. 

The  stomach  lies  in  the  epigastrium  and  the  left  hypo- 
chondrium  ;  five-sixths  are  to  the  left  of  the  median  line ;  only  a 
small  part  of  the  pyloric  portion  is  on  the  right  side.  It  lies 
under  the  liver  and  diaphragm,  above  the  jejunum,  ileum,  and 
colon,  and  extends  from  the  spleen  to  the  gall-bladder. 

The  cardia  lies  one  inch  (2-3  cm.)  below  the  esophageal 
opening  in  the  diaphragm,  11  cm.  from  the  anterior  body-wall ; 
this  point  is  also  opposite  the  seventh  left  chondro-sternal 
junction  or  the  eleventh  thoracic  vertebra — three  landmarks. 
The  fundus  is  3-5  cm.  higher  up,  at  the  sixth  left  chondro- 
sternal  junction.  Pylorus  reaches  the  upper  border  of  the 
first  lumbar  vertebra  on  the  right  side.  Lowest  edge  of  the 
greater  curvature  in  the  median  line  reaches  a  point  two 
fingers'  breadth  above  the  umbilicus. 

Relations:  above  and  anferiorbj,  diaphragm,  anterior  parts 
of  the  seventh,  eighth,  and  ninth  ribs,  thoracic  and  abdominal 
walls,  left  part  of  the  under  surface  of  the  liver ;  posteriorly^ 
diaphragm  and  its  left  crus,  aorta,  inferior  vena  cava,  celiac 
axis,  lesser  sac  of  the  peritoneum,  transverse  colon,  and  splenic 
flexure,  transverse  meso-colon  (upper  layer),  part  of  the  spleen, 
splenic  vessels,  pancreas,  left  kidney  and  capsule;  at  the  left 
end  are  the  spleen  and  diaphragm. 

How  many  coats  has  the  stomacli  ? 

Four,  as  follows : 

Serous,  derived  from  the  peritoneum  covering  all  parts 
except  along  the  greater  and  lesser  curvatures,  where  the 
omenta  leave  triangular  spaces,  along  which  pass  the  vessels 
and  nerves. 

Muscular,  consisting  of  three  sets  of  fibers:  the  longitudinal^ 
continuous  with  the  longitudinal  coat  of  the  esophagus  and 
small  intestine,  more  distinct  along  the  lesser  curvature  ;  the 
circular  fihers  form  a  continuous  layer  beneath  the  former  set, 
most  abundant  at  the  pyloric  end,  forming  the  sphincter;  the 
oblieiue  fibers,  some  passing  obli({uely  from  left  to  right,  others 


272  ESSENTIALS  OF  HUMAN   ANATOMY. 

vice  versa,  around  the  cardiac  orifice  ;  the  submucous  coat  con- 
sists of  areolar  tissue  supporting  tlie  vessels. 

Mucous,  covered  with  columnar  epithelium,  and  thrown  into 
longitudinal  folds  or  rug;ie  when  the  stomach  is  empty,  covered 
by  small,  shallow,  polygonal-shaped  alveoli  from  0.12  mm.  to 
0.25  mm.  in  diameter  ;  they  are  the  mouths  of  the  tubular 
glands. 

The  gastric  glands  are  of  three  kinds  :  the  cardiac  (not  called 
peptic)  are  lined  throughout  with  columnar  epithelium,  con- 
sisting of  a  duct  into  which  open  two  or  three  cecal  tubes; 
beneath  the  epithelium  lie  large,  spheroidal,  granular,  jjarietal 
cells  ;  these  glands  are  found  in  all  parts  of  the  stomach. 

Pyloric  glands,  found  in  greatest  numbers  at  the  pyloric  end, 
resemble  the  preceding,  but  are  without  the  large  parietal  cells, 
and  the  cecal  tubes  are  shorter  and  more  numerous. 

Lenticular  glands  or  lymphoid  follicles  exist  in  early  life, 
consisting  of  masses  of  lymphoid  tissue  like  a  solitary  gland. 

Give  the  blood-  and  nerve-supply. 

The  five  arteries  are :  coronary,  pyloric,  right  gastro-epiploic 
of  the  hepatic,  left  gastro-epiploic,  and  vasa  brevia  from  the 
splenic. 

The  veins  end  in  the  splenic,  superior  mesenteric,  gastric, 
and  portal  veins. 

The  nerves  are  the  terminal  branches  of  both  pneumogastrics 
and  numerous  branches  from  the  sympathetic  of  the  solar 
plexus. 

The  Small  Intestine. 
Describe  it  (Fig.  116). 

It  is  the  narrowest  part  of  the  digestive  tract,  is  a  convo- 
luted tube  twenty-two  feet  long,  occupying  the  central  and 
lower  parts  of  the  abdominal  and  pelvic  cavities,  and  is  sus- 
pended from  the  spine  by  a  fold  of  peritoneum  called  the  mes- 
entery ;  its  three  divisions  are  the 

Duodenum'^,  ten  to  twelve  inches  long,  with  three  types,  cir- 
cular, or  infantile,  \}-shaped,  and  y-shap>ed,  passing  upward  and 
backward  to  the  right  to  the  under  surface  of  the  liver  and 
gall-bladder — superior  curve — then  descending  in  front  of  the 
right  kidney — descending  portion — thence  running  transversely 
across  the  third  or  fourth  lumbar  y^xX^hxix^transverse  portion — 


THE  SMALL   INTESTINE. 


273 


to  endin  the  jejunum  on  the  left  side  of  the  first  or  second  lum- 
bar vertebra — ascending  portion — a  fifth  portion  is  sometimes 
described,  about  one  inch  long,  which  arches  forward  to  join  the 
jejunum.  It  is  only  partially  covered  by  peritoneum,  has  no 
mesentery,  and  surrounds  the 
head  of  the  pancreas  ;  into  the 
descending  portion,  to  the  inner 
side,  pass  obliquely  the  common 
bile  and  pancreatic  ducts. 

Jejunum^ ^  so  called  because 
usually  empty  after  death,  in- 
cludes the  upper  two-fifths  of 
the  remainder  of  the  small  intes- 
tine, and  lies  chiefly  in  the  um- 
bilical region  and  left  iliac  fossa. 

Ueura^  includes  the  remainder 
(three-fifths)  of  the  small  intes- 
tine, is  named  from  its  numerous 
coils,  occupies  chiefly  the  umbil- 
ical, hypogastric,  right  iliac,  and 
occasionally  pelvic  regions,  and 
opens  into  the  inner  side  of  the 
commencement  of  the  large  in- 
testine in  the  right  iliac  fossa ; 
the  orifice  is  guarded  by  a  two- 
leaved  ileo-cecal  valve,  or  valve  of 
Bauliin. 

What  coats  has  the  small  intes- 

tme  .  Yio.  116.— The  intestinal  canal. 

J  he    same    as   the  stomach —  (Lei.iy.) 

mucous,  submucous,  muscular,  and  serous. 

The  mucous  memhrane  is  covered  with  columnar  epithelium, 
and  forms  transverse  folds  encircling  the  tube  for  one-half  or 
two-thirds  of  its  circumference,  forming  the 

I'alculfn  conniventes ;  they  are  absent  in  the  first  two  inches 
of  the  duodenum  and  almost  disappear  in  the  lower  part  of  the 
ileum  ;  villi  cover  the  surface,  formed  of  a  central  lacteal  ves- 
sel accompanied  by  unstriped  muscular  tissue,  an  encircling 
plexus  of  ca[)illaries,  lymphoid  tissue,  and  granular  corpuscles, 
all  enclosed  by  a  basement-membrane  supporting  columnar 
epithelium:   their  number  is  estimated  at  four  million;   the 

18 


274  ESSENTIALS  OF  HUMAN   ANATOMY. 

Si(hmiicoiis  coat  connects  the  mucous  with  the  muscular  coat, 
and  contains  the  intestinal  vessels  and  nerve-plexuses ;  the 

Muscular  coat  externally  is  composed  of  longitudinal  and 
internally  of  circular  libers,  Ibrming  complete  rings. 

Describe  the  glands  of  the  small  intestine. 

They  are  : 

BrunnerH  ghuuh,  resembling  the  salivary  in  structure,  are 
limited  to  the  duodenum  and  commencement  of  the  jejunum. 

Ci'i/pts,  or  glaiuh  of  Licbcrk'dliii^  are  minute  tubular  depres- 
sions lined  with  columnar  epithelium,  found  in  both  intestines, 
small  and  large. 

Solltari/  glanth^  most  numerous  in  the  lower  part  of  the 
ileum,  but  found  in  all  parts,  consist  of  masses  of  lymphoid 
tissue  like  a  l^mph-node,  O.G  mm.  to  3  mm.  in  diameter. 

Pcyers  glands  or  patclics  are  twenty  to  thirty  ovoidal  patches 
composed  of  numerous  solitary  glands  (hence  named  agminated 
glands),  situated  opposite  to  the  mesenteric  attachment,  their 
lonu'  axis  leno-thwise,  and  are  lariiiest  and  most  numerous  in  the 
ileum,  although  occasionally  seen  in  the  jejunum  and  duo- 
denum ;  the  valvulae  conniventes  and  villi  cease  at  the  margins 
of  the  patches. 

Name  the  blood-vessels  and  nerves. 

The  arteries  are  the  pyloric  and  from  the  gastro-duodenal 
of  the  hepatic  and  superior  mesenteric  ;  the  veins  chiefly 
empty  into  the  portal  system  ;  the  nerves  are  from  the  supe- 
rior mesenteric  plexus  of  the  sympathetic. 

The  Large  Intestine. 

Describe  it^^^  MFig-  H^)- 

It  extends  from  the  ileum  to  the  anus,  is  five  or  six  feet 
long,  large  and  sacculated,  and  has  the  same  coats  as  the  small 
intestine;  the  mucous  coat  is  destitute  of  villi,  but  is  thrown 
into  crescentic  folds  by  the  longitudinal  muscular  fibers,  which 
are  disposed  in  three  bands  (taenia),  shorter  than  the  other 
coats,  so  forming   them   into  pouches. 

Describe  the  subdivisions  of  the  colon. 

They  are  the  cecum^,  or  cajmt  coll,  the  dilated  commence- 


THE  LARGE   INTESTINE.  275 

ment  of  the  large  bowel  situated  in  the  right  iliac  fossa,  and 
usually  wholly  covered  by  peritoneum. 

The  appendix  vermi/ormis'^,  a  narrow,  blind-ended,  worm- 
like tube,  from  three  to  six  inches  long,  springing  from  the 
lower  back  part  of  the  cecum,  held  in  no  set  position  by  a 
peritoneal  fold. 

The  ileo-cecal  valve  (or  Bauhin's)  is  formed  by  two  hori- 
zontal semilunar  folds  of  mucous  membrane  at  the  termination 
of  the  ileum  in  the  cecum,  opening  toward  the  large  intestine 
and  guarding  against  reflux  from  the  large  into  the  small 
bowel ;  the  mucous  folds  are  reinforced  by  circular  muscular 
fibers,  and  the  surfaces  toward  the  ileum  are  covered  with 
villi,  while  these  are  absent  on  the  cecal  side. 

The  ascending  colon ''  extends  up  from  the  cecum  in  front  of 
the  right  kidney,  to  the  under  surface  of  the  liver  to  the  right 
of  the  gall-bladder,  where,  abruptly  bending  to  the  left,  it  forms 
the  h'pafic  flexure;  it  is  almost — sometimes  entirely — en- 
veloped in  peritoneum,  in  which  latter  event  it  has  an  ascend- 
ing meso-colon  (26  per  cent.). 

The  transverse  colon  ^  traverses  the  abdomen  from  right  to 
left,  just  below  the  liver,  stomach,  and  spleen,  to  the  left  hypo- 
chondriac region,  where  it  curves  downward  beneath  the  lower 
end  of  the  spleen,  forming  the  splenic  flexure  ;  it  has  a-  wide 
transverse  meso-colon^  attaching  it  to  the  spine  and  pancreas. 

The  descending  colon  "^  passes  down  in  front  of  the  left  kid- 
ney to  the  left  iliac  fossa  and  is  only  partially  covered  with 
peritoneum,  its  posterior  surface  usually  being  free;  the  de- 
scending meso-colon  is  rare. 

The  sigmoid  flexure^^^  the  narrowest  part,  lies  in  the  left 
iliac  fossa  extending  from  the  descending  colon  at  the  crest  of 
the  ileum  to  the  left  sacro-iliac  synchondrosis  ;  it  is  curved  like 
an  S,  and  is  held  in  place  by  a  loose  peritoneal  fold,  the  sig- 
moid meso-colon. 

The  rectiun^^  extends  from  the  left  sacro-iliac  articulation  to 
the  anus,  is  from  six  to  eight  inches  long,  curves  slightly  to 
the  right  and  then  adapts  itself  to  the  sacral  curve,  and  at  the 
apex  of  the  prostate  gland  inclines  backward  to  the  anus;  it  is 
non-.?acculated,  but  just  above  the  anus  presents  a  dilatation, 
or  ampulla  ;  it  is  only  covered  with  peritoneum  to  its  second 
portion,  forming  a  meso-rectuni ;  it  leaves  it  wholly,  to  be  re- 
flected upon   the  bladder  or  uterus,  three  and  one-half  inches 


276  ESSENTIALS  OF  HUMAN   ANATOMY. 

(8  cm.)  from  the  anal  orifice.  The  rectum  has  three  parts : 
the  Jint  continues  from  tlie  sigmoid  to  the  tliird  sacral  vertebra  ; 
the  second  from  there  to  the  apex  of  the  prostate  gland  ;  the 
f/n'rd  poifum  is  the  <iu(d  canal ^  one  inch  long. 

The  appendices  epiploicrX  are  little  peritoneal  pouches  filled 
with  fat  placed  along  the  colon  and  upper  part  of  the  rectum. 

What  guards  the  anal  orifice? 

The  sphincter  aui,  a  voluntary  muscle,  and  the  internal 
sphincter,  the  continuation  of  the  circular  muscular  coat. 

What  are  the  folds  of  Houston  ? 

Three  semilunar  folds  of  mucous  membrane,  one  on  the 
right  side  of  the  rectum  or  third  sphincter ;  two  more  are  on 
the  left  side,  one  above  the  level  of  the  right  fold,  and  one  below. 

Name  the  glands  of  the  large  intestine. 
Crypts  of  Lieberk'dhn  and  sulitart/  gkuids. 

Give    the    blood-  and    nerve -supply  of  the  large  intestine 
and  rectum. 

The  arteries  are  branches  of  the  superior  and  inferior  mesen- 
teric^ the  middle  hemorrhoidal  from  the  internal  iliac,  and  the 
inferior  hemorrhoidal  from  the  internal  pudic,  and  a  few  more 
from  the  sciatic. 

The  veins  empty  into  the  portal  system,  except  the  inferior 
hemorrhoidal. 

The  nerves  come  from  the  sympathetic  plexuses  around  the 
mesenteric  arteries,  and,  in  the  case  of  the  rectum,  the  fourth 
anterior  sacral  nerve  and  internal  pudic  supply  the  sphincter 
ani  muscle. 

The  Liver. 

Describe  it  (Figs.  117  and  119). 

It  occupies  the  right  hypochondrium  extending  across  the 
epigastrium  into  the  left  hypochondrium  to  the  mammary  line. 
It  is  the  largest  gland  in  the  body,  weighing  from  three  to  four 
pounds;  its  transverse  diameter  is  eleven  inches  (28  cm.),  its 
antero-posterior  eight  (20  cm.),  its  greatest  vertical  five  to 
seven  inches.  Covered  by  peritoneum,  except  at  the  attach- 
ments of  the  ligaments,  it  possesses  sl  fibrous  coat,  covering  the 
whole  organ  continuous  with  the  capsule  of  Glisson  at  the  trans- 


THE  LIVER. 


277 


verse  fissure  ;  there  are  three  surfaces,  an  anterior  border,  right 
and  left  ends,  five  fissures,  five  lobes,  five  ligaments,  and  five 
sets  of  vessels. 

Superior  surface  is  convex,  smooth,  lying  in  contact  with  the 
diaphragm  above,  and  below  with  a  small  portion  of  the  ab- 
dominal wall ;  it  is  divided  into  two  unequal  lobes  by  a  peri- 
toneal fold,  the  suspensory,  hroad,  or  falciform  ligament;  the 

Inferior  surface  is  concave,  is  in  relation  with  the  stomach. 


Gastric 
surfiice     /  /■ 
Tuber  pupil-    l^r 

Inre 
Tuber  omen-  J 
tcUe 


Xon-periioneal 

surface 
Im}>.    snpra-ren. 
(non-perit.) 

Imp.  supra -ren. 
Tiiipressio  renalls 
Imp.  duodenalis 

Impressio  celica 


Impressio  pylorica 
Fig.  117— Posterior  and  inferior  surfaces  of  the  liver. 

duodenum,  hepatic  flexure  of  the  colon,  right  kidney,  and  su- 
prarenal capsule,  and  is  divided  by  the  left  longitudinal fssure^,^, 
into  a  right  and  a  left  lobe. 

The  posterior  surface^;''  is  rounded  and  grooved,  presents  a 
margin  of  the  left  lobe,  a  groove  for  the  esophagus,  the  liga- 
mentum  venosum  in  the  fissure  of  the  ductus  venosus^  the 
Spigelian  lobe,  a  fossa  for  the  vena  cava,  a  small  non-peritoneal 
surface  for  part  of  the  right  suprarenal  capsule,  and  a  large  one 
for  the  diaphragm. 

Anterior  border^  is  thin,  sharp,  and  deeply  notched  at  the 
site  of  the  round  ligament  and  of  the  gall-bladder  at  the  ninth 
costal  cartilage  ;  it  correspctnds  usually  with  the  margins  of  the 
ribs  in  males,  projecting  a  little  lower  in  women  and  children. 

Describe  the  ligaments. 

Tlicy  are  five  in  number  (really  ten),  four  being  composed 
of  folds  of  the  peritoneum  ;  the  fifth  is  the  obliterated  umbilical 
vein  ;  the 


278  ESSENTIALS  OF  HUMAN   ANATOMY. 

Sufipensory  or  broad  Ugament  (falciform)  is  a  falciform  an- 
tero-posterior  peritoneal  fold,  with  its  apex  backward,  attached 
to  the  liver  from  the  notch  on  the  anterior  border  to  the  coro- 
nary ligament — its  anterior  free  edge  enveloping  the  round  liga- 
ment— and  to  the  diaplivagm  and  sheath  of  the  right  rectus 
muscle  as  low  as  the  umbilicus ;  the 

Coronary  Ujomeuts  consist  of  two  layers  reflected  from  the 
diaphragm  on  the  upper  and  lower  margins  of  the  posterior 
surface  of  the  organ,  between  which  firm  areolar  tissue  binds 
the  liver  to  the  diaphragm  ;  the 

Lateral  ligaments^  right  and  left  triangular^  are  prolongations 
on  each  side  of  the  two  layers  of  the  coronary,  which  unite 
and  extend  from  the  diaphragm  to  the  adjacent  posterior  sur- 
face of  the  liver. 

Round  ligament^  a  fibrous  cord,  ascends  from  the  umbilicus 
in  the  anterior  free  maro;in  of  the  broad  liirament  to  the  lono-i- 
tudinal  fissure,  traceable  back  to  the  vena  cava  ;  the  posterior 
portion  is  the  remains  of  the  ductus  venosus,  the  anterior  of 
the  umbilical  vein. 

Describe  the  fissures. 

They  are  five  in  number,  dividing  the  posterior  and  inferior 
surfaces  of  the  organ  into  five  lobes ;  they  resemble  the  letter 
H. 

Left  longifiidlnal  Jissnre^^^  extends  from  the  notch  on  the 
anterior  border,  inferiorly  and  posteriorly  to  the  posterior  mar- 
gin of  the  superior  surface,  separating  the  right  and  left  lobes, 
and  is  joined  by  the  f ran sverse  fissure  ^'^ ;  the  anterior  portion  of 
the  fissure  is  called  the  nmhilical  fissure  from  lodging  the  fetal 
umbilical  vein  ;  posterior  portion,  the  y7S.s?<re  of  the  ductus  veno- 
sus, lodging  the  obliterated  fetal  vessel ;  either  part  is  often 
partially  bridged  over  by  the  pons  hepatis. 

Transverse  fissure^'^,  porta,  hepatis,  or  hihmi,  is  two  inches  long 
and  one-half  inch  wide,  passing  transversely  across  the  under 
surface  of  the  right  lobe  between  the  two  longitudinal  fissures  ; 
here  enter  the  portal  vein,  hepatic  artery,  and  nerves,  and  the 
bile-ducts  and  lymphatics  emerge. 

Fissure  of  the  gall-bladder^*,  fossa  vesicalis,  lies  parallel  and 
to  the  right  of  the  umbilical  fissure  reaching  back  nearly  to 
the  transverse  fissure. 

Fossa  for  the  vena  cava  is  short  and  deep,  sometimes  con- 


THE  LIVER.  279 

verted  into  a  canal ;  it  separates  the  Spigelian  from  the  right 
lobe,  and  is  separated  from  the  transverse  fissure  by  the  cau- 
date lobe ;  the  hepatic  veins  here  empty  into  the  vena  cava. 
These  two  fossae  form  an  interrupted  right  longitudinal  fissure. 

Describe  the  lobes  of  the  liver. 

They  are  five  in  number ;  the 

Right  lobe^,  the  largest,  of  a  quadrilateral  form,  its  surfaces 
being  superior,  inferior,  and  posterior,  marked  by  three  fissures, 
viz.  transverse,  one  for  the  gall-bladder,  and  one  for  the  inferior 
cava,  which  separate  three  more  lobes ;  four  impressions  are 
seen  on  the  under  surface  ;  posteriorly,  the  renal  and  supra- 
renal; anteriorly,  one  for  the  colon;  internally,  one  for  the 
duodenum. 

Left  lohe},  smaller  and  flattened,  resting  by  its  inferior  con- 
cave surface  on  the  stomach,  presenting  a  prominence,  the  tuher 
omejitale. 

Lohus  quadrafus^  is  marked  oif  from  the  under  surface  of  the 
right  lobe  by  the  transverse  fissure  behind,  by  that  for  the 
gall-bladder  on  the  right,  and  anterior  part  of  the  longitudinal 
fissure  on  the  left. 

Lohus  Spigelii^  projects  from  the  posterior  surface  of  the 
right  lobe,  bounded  in  the  front  by  the  transverse  fissure,  on 
the  right  by  that  for  the  vena  cava,  and  on  the  left  by  the 
fissure  of  the  ductus  venosus. 

Lohus  caiidatus^  is  a  small  elevation  running  obliquely  out- 
ward from  the  base  of  the  lobus  Spigelii  to  the  under  surface 
of  the  right  lobe  ;  it  intervenes  between  the  right  end  of  the 
transverse  fissure  and  the  commencement  of  that  for  the  vena 
cava. 

Describe  the  vessels  of  the  liver. 

They  number  five,  hepatic  artery,  portal  vein,  hepatic  veins, 
hepatic  duct,  and  the  lymphatics ;  the  first  three  are  enveloped 
in  loose  an^olar  tissue  called  the  capsule  o/ 6V/.s-.so»,  which  ac- 
companies the  vessels  through  the  p)ort<d  canals  in  the  interior 
of  the  organ. 

rortal  rriii^^  (vein  of  the  gate),  about  four  inches  long,  col- 
lects blood  from  the  viscera  of  digestion  ;  it  is  formed  by  the 
junction  of  the  superior  mesenteric  and  splenic  veins,  the  lat- 
ter  receiving   the  bhxxl  returned   ])y   the  inferior  mesenteric 


280 


ESSENTIALS  OF  HUMAN  ANATOMY. 


vein,  while  the  cystic  and  two  gastric  veins  empty  into  the 
portal  vein  itself.  Entering  the  transverse  fissure  it  divides 
into  branches  for  the  right  and  the  left  lobes,  which  receive  the 
vaginal  and  capsular  veins,  and  subdividing  form  the  interlobu- 
lar veins^  (^'ig-  118),w^hich  send  branches  to  the  interior  of 


^:^/W  ijW 


Fig.  118.— Cross-section  of  a  lobule  of  the  liver  (Leidy). 

each  lobule,  forming  a  plexus  converging  to  empty  into  the 
central  intralohular  vein''  running  at  right  angles  to  other  ves- 
sels ;  the  intralobular  vein  empties  into  a  auhlohidar  vein,  a 
radicle   of  the  hepatic  vein  ;    the 

Uejyatic  veins  commence  in  sublobular  veins  as  just  described, 


THE   LIVER.  281 

which  unite  to  form  three  large  and  several  smaller  branches 
terminating  in  the  inferior  vena  cava  in  the  fissure  for  that 
vessel. 

Hepatic  artery^''  springs  from  the  celiac  axis,  enters  the 
transverse  fissure,  and  divides  into  branches  which  ramify  in 
the  capsule  of  Glisson ;  vugiiud,  supplying  nutriment  to  the 
vessels,  ducts,  etc. ;  capmlar  to  terminate  in  the  external  fibrous 
coat ;  inferhhular  pass  to  the  interlobular  plexus  on  the  outer 
surface  of  each  lobule;  doubtful  if  any  branches  enter  the 
capillary  network  between  the  cells. 

Hepatic  duct^^  is  formed  by  the  union  of  two  bile-ducts  of 
nearly  equal  size  which  emerge  from  the  transverse  fissure,  one 
from  the  right,  the  other  from  the  left  lobe  ;  it  passes  down- 
ward to  the  right  for  one  to  two  inches,  to  be  joined  by  the 
cystic  duct  from  the  gall-bladder,  forming  the  ductus  communis 
choledochus. 

Lymphatics  consist  of  a  superficial  or  subperitoneal  and  a  deep 
or  interlobular  set  accompanying  the  blood-vessels,  emerging 
with  the  hepatic  veins  and  at  the  portal  fissure. 

Whence  do  the  nerves  of  the  liver  come  ? 

From  the  solar  plexus  of  the  sympathetic  and  from  the  left 
pneumogastric ;  the  phrenics  supply  part  of  the  external 
surface. 

Describe  the  liver  structure. 

It  is  composed  of  numerous  lobules  from  one-twentieth  to 
one-tenth  of  an  inch  in  diameter,  of  irregular  form  in  the  human 
liver,  polygonal  in  pigs,  their  bases  clustered  round  the  sub- 
lobular  vein,  to  which  each  is  connected  by  its  intralobular 
vein  ;  the  lobules  are  bound  together  by  loose  areolar  tissue  ; 
each  lobule  consists  of  nucleated  hepatic  ce/ls,  spheroidal  or 
many-sided,  with  nucleoli,  measuring  from  one  two-thousandth 
to  one  one-thousandth  of  an  inch,  containing  granular  yellow 
coloring-matter  and  globules,  which  cells  lie  in  the  meshes  of 
the  dense  capillary  network  occupying  its  interior;  spaces  be- 
tween the  cells  form  the  interceUn/ar  Miliary  passages",  bile- 
canaliculi,  the  radicles  of  the  bile-ducts. 

What  is  the  capsule  of  Glisson  ? 

The  areolar  tissue  which  surrounds  the  three  vessels  in  the 
right  free  margin  of  the  lesser  omentum,  entering  the  trans- 


282  ESSENTIALS  OF  HUMAN   ANATOMY. 

verse  fissure,  forms  poit<d  canals  for  the  same  vessels  to  their 
ultimate  ramifications,  and  is  continuous  with  the  fibrous  coat 
of  the  organ.  In  a  section  of  liver-tissue  the  portal  may  be 
distinguished  from  the  hepatic  veins  by  the  fact  that  the 
former  are  collapsed,  being  surrounded  by  the  capsule  of  Glis- 
son,  while  the  hepatic  are  held  open,  being  closely  connected 
with  the  liver-substance. 

Describe  the  gall-bladder^*. 

It  is  a  pear-shaped,  fibro-muscular  receptacle  for  the  bile  ;  its 
fundus  and  under  surface  of  the  body  and  neck  are  covered  by 
peritoneum,  while  its  interior  is  lined  with  a  cylindrical-celled, 
epithelial-coated  mucous  membrane,  presenting  a  honeycombed 
appearance  from  the  confluence  of  numerous  minute  rugae  ;  its 
length  is  from  three  to  four  inches,  its  capacity  from  eight  to 
twelve  fluidrachms,  and  it  lies  in  a  fossa  on  the  under  surface 
of  the  liver,  its  fniulus — most  dilated  portion — projecting 
slightly  beyond  the  anterior  border,  touching  the  abdominal 
wall  just  below  the  ninth  costal  cartilage ;  the  narrow  neck 
curves  upon  itself  like  an  italic  _/',  to  terminate  in  the  c?/sh'c 
f7?/c^,  which  is  one  to  three  inches  long,  and  is  lined  by  mucous 
membrane  so  disposed  in  a  series  of  creseentic  folds  as  to 
present  the  appearance  of  a  spiral  valve^  which  is  called  the 
valve  of  Heister ;  the  cystic  duct  joins  the  hepatic  duct  to 
form  the  common   bile-duct. 

Describe  the  ductus  communis  choledochiis  ^^  (Ficr.  ]]7). 

It  is  about  three  inches  long,  three-sixteenths  of  an  inch  in 
diameter,  and  is  formed  by  the  junction  of  the  hepatic  and 
cystic  ducts ;  it  opens  usually  by  a  common  orifice  with  the 
pancreatic  duct,  from  a  small  sac  of  mucous  membrane  and 
papilla  Vateri  a  little  below  the  middle  of  the  inner  side  of  the 
descending  portion  of  the  duodenum;  its  walls  are  composed 
of  fibrous  with  a  little  muscular  tissue,  its  mucous  membrane 
is  covered  with  columnar  epithelium,  and  it  runs  between  the 
layers  of  the  gastro-hepatic  omentum. 

What  are  the  relations  of  the  liver  ? 

Aufcro-siiperiorlf/,  diaphragm,  right  and  left  lyngs.  peri- 
cardium and  heart,  anterior  abdominal  wall,  six  or  seven  right 
lower  ribs  ;  iiiferiorly^  right  kidney  and  capsule,  hepatic  flexure 
of  colon,  duodenum,  gall-bladder  and  cystic  duct,  vessels  at  the 


THE  PANCREAS. 


283 


transverse  fissure,  stomach  ;  posteriorly,  diaphragm  and  crura, 
tenth  and  eleventh  thoracic  vertebrae,  esophagus,  aorta,  inferior 
vena  cava,  thoracic  duct. 

The  Pancreas. 

Describe  the  pancreas'*  (Fig.  119). 

It  is  a  compound  racemose  gland,  of  pyramidal  shape,  about 
six  inches  long,  one  and  a  half  inches  wide,  and  one  inch  thick. 


Fio.  119.— View  of  duodenum  and  pancreas. 


is  indicated  by  dotted  lines  (Testut) .  ^.quadrate  lobe;  B,  ri 
right  and  left  suprarenal  capsules;  A  left  kidney  ;  A,  pancri 


The  part  of  stomach  removed 
['  lobe;  B,  right  kidney;  (\(  ' , 


reas;  /',  U])per  i>art 


17,  ve'na'cava  inferior;  IK,  inferior  mesenteric  vessels;  ]".♦,  spermatic  vessels. 


lying  behind  the  stomach  and  in  front  of  the  second  lumbar 
vertebra.  It  is  compo.sed  of  lobules  connected  by  areolar 
tissue,  each  lobule  consisting  of   an   ultimate  branch  of  the 


284  ESSENTIALS  OF  HUMAN  ANATOMY. 

duct  lined  with  columnar  epithelium,  terminating  in  cecal 
pouches  or  acini,  also  lined  with  cylindrical  epithelium,  outside 
of  which  is  a  line  capillary  network  ;  the 

Pancreatic  duct  (canal  of  WirsiiJi(/)  extends  the  whole  length 
of  the  gland  and  opens  into  the  descending  part  of  the  duode- 
num, to  the  inner  side,  with  the  common  bile-duct;  the 

Head,  or  n'(/ht  extremity,  is  embraced  by  the  concavity  of  the 
duodenum,  the  common  bile-duct  lying  behind,  the  superior 
and  inferior  pancreatico-duodenal  arteries  in  front.  A  part  of 
the  head  may  curve  behind  the  superior  mesenteric  vessels  and 
be  partially  detached,  the  lesser  pciucreas.  The  ta'di  or  left 
extremity^  reaches  the  spleen  either  across  the  upper  end  of 
the  left  kidney  and  capsule  or  across  the  center  of  the  kidney, 
touching  same  part  of  the  spleen  in  each  case.  The  neck  is  one 
inch  long,  constricted  between  the  first  and  last  portions  of  the 
duodenum.  The  hady  is  triangular  on  section,  with  its  apex 
forward,  placed  at  the  point  of  separation  of  the  two  layers  of 
the  transverse  mesocolon ;  it  presents  three  surfaces,  anterior, 
2)oster{or,  and  a  narrow  inferior^  and  three  borders,  superior, 
anterior,  and  inferior.  Relations :  above,  first  part  of  the 
duodenum,  celiac  axis,  solar  plexus,  splenic  and  hepatic  arte- 
ries, left  lobe  of  the  liver;  in  front,  lesser  sac,  stomach,  pan- 
creatico-duodenal arteries,  transverse  colon,  upper  layer  of  the 
transverse  mesocolon;  heloic,  duodenum, -jejunum,  transverse 
colon,  lower  la3'er  of  the  transverse  mesocolon,  superior 
mesenteric  vessels,  inferior  mesenteric  vein,  mesentery  ; 
behind,  second  lumbar  vertebra,  pancreatic  and  common  bile- 
ducts,  aorta,  vena  cava,  origin  of  the  thoracic  duct,  vena 
portae,  crura  of  the  diaphragm,  solar  plexus,  superior  mesen- 
teric artery,  right  and  left  renal  vessels,  left  kidney  and  cap- 
sule ;  spleen  at  the  left  end,  curve  of  the  duodenum  at  the 
right  end. 

The  arteries  are  derived  from  the  hepatic,  splenic,  and  supe- 
rior mesenteric  ;  I'ejns  are  of  the  same  names  and  empty  into 
the  portal  system  ;  nerves  come  from  the  solar  plexus.  In 
structure  the  pancreas  resembles  the  parotid  gland. 

The  Ductless  Glands. 

What  are  the  ductless  glands  ? 

The  spleen,  suprarenal  capsules,  thyroid  and  thymus  glands, 
bodies  whose  functions  are  uncertain  and  which  have  no  ducts. 


THE  SPLEEN.  285 

The  spleen  and  suprarenal  capsules  lie  in  the  abdominal 
cavity,  but  the  glands  Avill  be  for  convenience  described  after 
the  spleen. 

The  Spleen  (Figs.  116  and  119). 

Describe  it. 

It  is  a  soft,  brittle,  very  vascular,  oblong,  flattened  organ 
embracing  the  fundus  of  the  stomach,  to  which  it  is  attached 
by  the  gastro-splenic  omentum,  which  completely  invests  the 
spleen,  except  at  the  hilum  and  where  the  suspensory  liga- 
ment is  attached  ;  the  organ  lies  deeply  in  the  left  hypochon- 
drium,  and  has  three  surfaces,  ^jA/'e«/c,  Lki.s(iI,  and  iiifcnial,  and 
three  borders. 

Outer  phrenic  surface  is  convex,  smooth,  lying  in  contact 
with  the  diaphragm,  Avhicli  separates  it  from  the  ninth,  tenth, 
and  eleventh  ribs ;  the 

Inner  surface  is  concave,  presents  the  hilnni  and  intermediate 
border  separating  a  posterior  renal  surface^i'rom  an  anterior 
gastric  surface. 

Hilum  is  a  vertical  fissure  pierced  by  blood-vessels,  lym- 
phatics, and  nerves. 

Basal  surface  bounds  the  lower  end  of  the  spleen,  touches 
the  pancreas,  rests  on  the  splenic  flexure  of  the  colon  and 
on  the  phreno-colic  ligament. 

Anterior  border  is  often  notched  ;  the  j^^sterior  border  is 
rounded  and  in  relation  with  the  left  kidney  ;  the 

Suspensory  ligament.^  a  peritoneal  fold,  connects  it  with  the 
under  surface  of  the  diaphragm. 

Tlic  sustentaculum  lienis  (supporter  of  the  spleen)  is  the 
phreno-colic  ligrrment,  which  passes  from  the  diaphragm  oppo- 
site the  anterior  ends  of  the  tenth  and  eleventh  ribs  to  the 
splenic  flexure  of  the  colon. 

Jldations:  externallg  and  <djove,  peritoneum  and  diaphragm, 
ninth,  tenth,  and  eleventh  ribs,  costo-phrenic  sinus,  left  lung 
and  pleura,  left  lobe  of  the  liver  (at  birth),  muscles  of  the 
back ;  internallf/,  stomach,  left  kidney  and  capsule,  tail  of 
the  pancreas  ;  inferiorly^  tail  of  the  pancreas  sometimes,  splenic 
flexure  of  the  colon,  phreno-colic  ligament. 

Fibro-clastic  voat^  l)en(!ath  the  serous,  wliich  intimately  ad- 
heres to  it,  forms  the  franuiwork  of  tlu^  spleen,  jiassing  inward 
at  the  hilum  with  the  vessels  as  sheaths,  from  which,  and  the 


286  ESSENTIALS  OF  HUMAN   ANATOMY. 

inner  surface  of"  the  capsule,  numerous  bands  or  trahecnlbe  pass, 
uniting  to  form  numerous  small  spaces  or  uitolyt  filled  with 
the  splenic  pulp. 

Describe  the  spleen-pulp  and  Malpighian  bodies. 

It  is  of  a  dark  reddisli-bruwn  culur,  and  under  the  microscope 
is  seen  to  consist  of  a  network  of  branched  connective-tissue 
cells,  containing  pigment-granules  (broken-down  blood-cor- 
puscles), granular  matter,  nucleated  cells,  free  nuclei,  and  red 
blood-cells  in  all  stages  of  disintegration  ;  the 

Splenic  artery'"^  (l^'ig-  H^)  is  large,  tortuous,  and  divides  at 
the  hilum  into  five  or  six  branches  wdiich  do  not  anastomose  to 
any  extent,  each  branch  breaking  up  again  and  again  into 
smaller  ones,  until  they  terminate  in  bundles  of  straight  ves- 
sels which  open  into  the  interstices  of  the  reticulum  formed 
by  the  branched  connective-tissue  cells. 

The  Molpiglikui  bodies  are  small,  rounded,  expanded  masses 
of  the  lymphoid  tissue  of  the  external  coat  of  the  small  splenic 
arteries,  from  one  one-hundredth  to  one  twenty-fifth  of  an  inch 
in  diameter,  usually  surrounding  the  vessel,  but  sometimes 
projecting  from  one  side ;  they  are  composed  of  a  delicate 
reticulum  packed  with  lymph-corpuscles  and  pervaded  by 
capillaries ;  the 

Splenic  vein,  arises  from  the  lacunar  spaces  in  the  pulp,  has 
free  anastomoses,  and  empties  into  the  portal  vein  ;  the 

Kerves  are  derived  from  the  right  pneumogastric  nerve,  the 
right  and  left  semilunar  ganglia,  the  solar  plexus,  and  attend 
the  arteries. 

Lynipliatics  form  two  sets,  trabecular  and  perivascular. 

The  Thyroid  Gland. 

Describe  it. 

It  con.sists  of  two  lateral  lobes  situated  at  the  sides  of  the 
upper  portion  of  the  trachea,  connected  at  about  their  lower 
thirds  by  a  narrow  transverse  portion,  the  isthntus.  which  is 
occasionally  absent.  A  third  lobe,  the  pyramid,  sometimes 
springs  from  the  left  upper  side  of  the  isthmus,  or  the  left 
lobe,  and  extends  to  the  hyoid  bone  ;  it  is  at  times  detached  ; 
occasionally  a  slender  muscular  band — the  levator  glandidse 
tltyroidesf: — extends  from  the  hyoid  bone  to  the  isthmus  or  the 
pyramid.     Structurally,   the    gland    consists   of  a   connective 


THE  THYMUS  GLAND.  287 

tissue  capsule,  sending  in  septa  subdividing  the  organ  into 
lobes,  each  of  which  is  formed  of  numerous  closed  vesicles 
filled  with  a  viscid  yellowish  fluid  embedded  in  connective 
tissue  containing  a  dense  vascular  plexus  surrounding  the 
vesicles. 

Two  jmnifJiT/rold  ffkuids  are  desGYihed  as  constant  in  man  and 
other  mammals,  each  lying   near  a  lateral  lobe  of  the  thyroid. 

What  arteries  supply  this  gland  ? 

The  superior  and  the  infrrior  thyroid  branches  respectively 
of  the  external  carotid  and  the  thyroid  axis,  and  at  times  the 
thijroidea  ima,  springing  either  from  the  innominate  artery  or 
the  aortic  arch  itself,  to  pass  up  on  the  front  of  the  trachea. 
These  vessels  are  remarkable  for  their  size  and  frequent 
anastomoses. 

Describe  the  veins  of  the  thyroid  gland. 

They  form  a  plexus  on  the  surface  of  the  gland,  whence 
arise  the 

Superior-  thyroid  vein,  )  ^       ^    .       •   ^    ^i     •   ^         i  •        i 
ar- 7  77   ^7-7      •      '  V  r-imptying into  the  internal  lugular  vein. 
Mid  die  thyroid  veni,     \         i    J     n  j    o 

Inferior  thyroid  vein  opening  into  the  innominate  vein. 

Name  the  nerves. 

Branches  of  the  middle  and  inferior  cervical  ganglia. 

The  Thymus  Gland. 

Describe  it. 

It  is  a  temporary  organ  of  unknown  function,  reaching  its 
full  development  at  the  end  of  the  second  year,  after  which  it 
gradually  atrophies,  having  nearly  disappeared  at  puberty. 
When  fully  developed  it  extends  from  the  fourth  costal  carti- 
lage to  the  lower  border  o{'  the  thyroid  gland,  consisting  of  two 
lateral  lobes  in  close  contact  along  the  middle  line,  while  some- 
times an  intermediate  lobe  exists  ;  the  sternum  and  origins  of 
the  sterno-hyoid  and  sterno-thyroid  muscles  cover  it,  as  it  lies 
in  the  neck  behind  these  muscles  upon  the  front  and  sides  of 
the  trachea;  it  rests,  in  the  mediastinum,  upon  the  pericar- 
dium, the  thoracic  fascia  separating  it  froni  the  aortic  arch  and 
great  vessels.  Its  dimensions  arc  :  length,  two  inches;  breadth, 
one  and  a  half  inches;  thickness,  one-quarter  of  an  inch;  at 
birth  it  weighs  about  half  an  ounce. 


288  ESSENTIALS   OF  HUMAN    ANATOMY. 

Describe  its  structure. 

It  is  formed  of  numerous  lobules  bound  together  by  delicate 
areolar  tissue,  all  being  ineloscd  by  a  fibrous  capsule  ;  the 
lobules  are  composed  of  a  cortiad  lymphoid  tissue,  and  a 
mrdnlldfij  portion  containing  a  few  lymphoid  cells,  but  toward 
the  center  granular  cells  and  concentric  corpuscles  exist.  Each 
follicle  is  surrounded  with  a  capillary  plexus. 

Describe  the  arterial  and  nerve-supply. 

The  <iit( rif'S  are  derived  from  the  internal  mammary,  supe- 
rior and  inferior  thyroid,  subclavian  and  carotid. 

The  veins  empty  into  the  thyroids  and  left  innominate. 

The  li/mphatics  are  large  and  arise  from  an  interlobular 
plexus  in  the  substance  of  the  gland,  and  are  said  to  empty 
into  the  internal  jugular  veins. 

The  nerccs  are  very  minute,  coming  from  the  pneumogastric 
and  sympathetic  ;  the  descendens  cervicalis  and  phrenic  prob- 
ably reach  the  capsule. 

The  Suprarenal  Capsules. 

What  are  they? 

Two  triangular  or  semilunar  flattened  bodies,  situated  behind 
the  peritoneum,  immediately  above  and  in  front  of  the  upper 
part  of  each  kidney  ;  the  right  one  is  triangular,  the  left,  cres- 
centic  and  larger.  They  consist  of  a  thin,  closely  adherent 
Jibrous  capsule,  which  sends  numerous  communicating  partitions 
inward,  a  corf  real  strid  a  medullar?/  portion  ;  the  former  contains 
columns  of  finely  granular  polyhedral  cells,  with  channels  be- 
tween them  and  the  fibrous  portions,  believed  to  be  lymph- 
sinuses  ;  the  medullar?/  p)ortioii  is  formed  of  stout  connective- 
tissue  bundles  between  which  lie  coarsely  granular  columnar 
and  branched  cells,  which  have  been  thought  to  communicate 
with  a  very  fine  nerve-plexus  found  in  the  medulla. 

With  what  parts  do  these  organs  lie  in  contact? 

The  anterior  surface  of  the  riglif  capsule  touches  the  under 
and  back  surfaces  of  the  right  lobe  of  the  liver,  is  partly 
covered  by  the  inferior  vena  cava,  and  at  the  internal  inferior 
angle  is  crossed  by  the  hepatic  curve  of  the  duodenum  ;  poste- 
riori?/ it  lies  on  the  diaphragm. 

The  left  capsule  has  iii  /ront   the  peritoneum  of  the  lesser 


THE   ABDOMINAL   CAVITY.  289 

sac,  stomach,  spleen,  upper  border  of  the  pancreas,  splenic 
artery  ;  poateriorli/  is  the  left  crus  of  the  diaphragm.  They  are 
related  by  their  inner  margins  to  the  great  splanchnic  nerves 
and  semilunar  ganglia,  on  the  right  side  touching  the  inferior 
vena  cava,  and  on  the  left  side  the  left  crus  of  the  diaphragm. 

Name  its  vessels  and  nerves. 

The  arteries  are  from  three  sources :  the  suprarenal  and 
branches  of  the  inferior  phrenic  and  renal  arteries  forming  a 
dense  capillary  network  in  the  interior ;  the 

Venous  capillaries  return  blood  from  the  medullary  venous 
plexus  by  a  single  suprarenal  vein  which  empties  into  the  in- 
ferior cava  on  the  right  side,  and  on  the  left  into  the  renal  vein. 

Nerves  are  very  numerous,  chiefly  distributed  to  the  medulla, 
and  are  derived  from  the  solar  and  renal  plexuses  and  the 
phrenic  and  pneumogastric  nerves,  having  developed  upon 
them  numerous  small  ganglia,  hence  the  opinion  held  by  some 
that  these  bodies  belong  to  the  sympathetic  nervous  system. 

The  Abdominal  Cavity. 

What  is  the  abdomen  ? 

An  ovoidal  cavity,  limited  above  by  the  diaphragm,  below  by 
the  brim  of  the  true  pelvis  ;  in  front  and  at  the  sides  by  the 
lower  ribs,  abdominal  and  iliac  muscles ;  behind,  by  the  verte- 
bral column,  psoas,  and  quadratus  lumborum  muscles;  it  is 
lined  with  peritoneum — a  serous  membrane — which  is  reflected 
to  form  partial  or  complete  investments  for  the  contained 
organs  or  viscera. 

Name  the  abdominal  viscera. 

Stomach,  Suprarenal  capsules, 

Intestines,  Aorta, 

Liver,  Inferior  vena  cava, 

Gall-bladder,  Thoracic  duct. 

Spleen,  Ileceptaculum  chyh, 

Pancreas,  Bladder  if  distended. 

Kidneys,'  Uterus  if  enlarged. 

Describe  the  openings  in  its  walls. 

They  are  the  umlnliad  for  the  fetal  umbilical  vessels,  ob- 
literated after  birth,  leaving  a  depression,  the  innhihcusj 
openiufj  for  the  inferior  vena' cava   in   the  diaphragm;    aortic 

19 


290  ESSENTIALS  OF  HUMAN   ANATOMY. 

opening^  behind  the  diaphragm  between  the  crura,  for  the 
aorta,  vena  azygos  major,  thoracic  duct,  and  sometimes  the 
left  sympathetic  nerve  ;  esopluigml  opening  in  the  diaphragm 
for  the  esophagus  and  pneumogastric  nerves ;  internal  abdomi- 
nal ring,  on  each  side,  for  the  spermatic  cord  in  the  male, 
round  ligament  in  the  female  ;  lacuna  vascularis,  on  each  side 
below  Poupart's  ligament  for  the  transmission  of  the  femoral 
vessels  and  crural  branch  of  the  genito-crural  nerve,  showing 
internally  the  femoral  or  crural  ring,  the  site  of  the  femoral 
hernia. 

Into  what  regions  is  the  abdomen  artificially  divided? 

Into  nine,  by  two  imaginary  parallel  lines  encircling  the 
body  on  a  level  with  the  ninth  costal  cartilages  and  summits  of 
the  iliac  crests,  and  two  other  parallel  lines  drawn  from  the 
cartilage  of  the  eighth  rib  on  each  side  to  the  center  of  Pou- 
part's ligament. 

Quain  takes  as  the  upper  horizontal  line,  infracostal,  between 
the  lowest  points  of  the  thoracic  border,  usually  the  tenth 
costal  cartilages ;  the  inferior  horizontal  line,  hi-iliac,  unites 
the  most  prominent  (not  highest)  points  of  the  iliac  crests ; 
this  line  cuts  the  fifth  lumbar  vertebra  and  is  one  and  one- 
quarter  inches  below  the  summits  of  the  crests  ;  vertical  lines 
are  mid-Poupart.  Morris  advises  the  same  line  above  and  the 
interspinous  line  below,  connecting  the  anterior  superior  spinous 
processes  of  the  ilia,  also  the  vertical  mid-Poupart  lines. 
Joessel's  horizontal  lines  are  infracostal  and  interspinous; 
vertical,  ascend  to  the  upper  horizontal  line  from  the  ilio- 
pectineal  eminences  (Fig.  120).  This  marks  ofi'  three  hori- 
zontal zones,  epigastric,  mesogastric,  and  hypogastric. 

The  right  lateral  regions  are,  from  above  downward  (see 
cut),  the 

Right  hypochondriac,  which  contains  the  right  lobe  of  the 
liver,  gall-bladder,  hepatic  flexure  of  the  colon,  and  upper  part 
of  the  right  kidney. 

Right  lumbar,  contains  the  ascending  colon,  lower  part  of  the 
right  kidney,  and  some  coils  of  the  small  intestine  (ileum). 

Right  inguinal  (^iliac),  contains  the  cecum,  often  the  appen- 
dix vermiformis,  and  end  of  the  ileum. 

The  median  regions  are : 

Epigastric^  contains  part  of  the  right  lobe  of  the  liver,  greater 


THE  ABDOMINAL  CAVITY. 


291 


part  of  the  left  lobe,  part  of  the  gall-bladder,  stomach,  middle 
and  pyloric  portions,  both  orifices,  first  two  parts  of  the  duo- 
denum, duodeno-jejunal  junction,  pancreas,  except  the  tail, 
upper  part  of  the  spleen,  part  of  the  kidneys,  suprarenal  cap- 
sules. 

Umhilical,  contains  the  transverse  colon,  part  of  the  great 
omentum  and  mesentery,  transverse  portion  of  the  duodenum, 


Fig.  120.— Regions  of  the  abdominal  cavity,  anterior  view  (after  Joessel). 

and  some  coils  of  the  jejunum  and  ileum,  part  of  both  kidneys 
with  ureters,  and  the  receptaculum  chyli. 

IfypofjaHtrlc^  contains  coils  of  the  small  intestine,  the  bladder 
in  children,  or  when  distended  in  adults,  ureters,  the  uterus 
during   the    latter   months   of  pregnancy,    often    the    cecum, 


292 


ESSENTIALS  OF  HUMAN   ANATOMY. 


appendix  vermiformis.  sigmoid  flexure  of  the  colon,  and  the 
upper  part  of  the  rectum. 

The  left  lateral  regions  from  above  downward  are : 

Left  liypocliondrlac^  contains  the  fundus  of  the  stomach, 
greater  part  of  the  spleen,  tail  of  the  pancreas,  splenic  flexure 
of  the  colon,  upper  part  of  the  left  kidney,  and  part  of  the 
left  lobe  of  the  liver. 

Left  lumbar,  contains  the  descending  colon,  part  of  the  omen- 
tum, sigmoid  flexure,  lower  part  of  the  left  kidney,  and  some 
coils  of  the  jejunum. 

Left  inguinal  (iliac),  contains  the  sigmoid  flexure  of  the 
colon  and  convolutions  of  the  jejunum  and  ileum. 

The  Peritoneum. 

Describe  it  (Fig.  121). 

A  serous  membrane,  forming  a  closed  sac  (in  the  7nale),  the 
layer  covering  the  walls  being  called  the  parietal,  and  that 

reflected   over  the  viscera  the 
^        .„     {v=j(.  viscend  \2iyeY  ;  it  is  coated  with 

a  layer  of  flattened  endothe- 
lium, its  attached  surface  being 
connected  with  the  subjacent 
parts  by  the  subperitoneal  areo- 
lar tissue  or  fascia. 

Does  the  peritoneum  always 
form  a  closed  sac? 

No  ;  in  the  female  the  Fal- 
lopian tubes  open  into  its  cavity. 

How  is  the  peritoneum  divided 
for  convenience  of  de- 
scription ? 

Into  the  greater  sac^^,  or  that 
covering  the  upper  anterior  por- 
tion of  die  liver^,  the  stomach^ 
in  front  and  above,  descending 

FIG.  i2i.-Diagrain  to  illustrate  over  the  ileum  forming  the  an- 
the  reflections  of  the  peritoneum  m  terior  layer  of  the  great  omen- 
thefen^aiebody  (Leidy).  ^^^^^^,5^  t],^  under  layer  of  the 

mesocolon"'^",  the  mesentery'',  and   reflections^^  upon   and  be- 


THE  PERITONEUM.  293 

tween  the  rectum  ^\  the  uterus  in  the  female'",  and  the  bladder'^, 
then  lining  the  antero-lateral  abdominal  walls  to  reach,  from 
the  under  surface  of  the  diaphragm  ^^,  the  upper  surface  of  the 
liver,  the  starting-point  of  this  description  (see  Fig.  121). 

The  lesser  cavity,  or  cavity  of  the  great  omeiifam^^^  starting 
from  the  diaphragm  behind,  passes  over  the  Spigelian  lobe  of 
the  liver '^,  then  covers  the  back  and  under  surface  of  the  stom- 
ach^, forms  the  inner  layer  of  the  great  omentum''',  passes 
over  the  colon''  completing  the  mesocolon ■^°,  and  thence  passes 
over  the  pancreas'*'  and  great  vessels  to  line  the  posterior  ab- 
dominal wall,  reaching  the  point  started  from  ;  the  two  cavities 
communicate  throuo'h  the  foramen  of  Winslow. 

Describe  the  foramen  of  Winslow '^ 

It  is  the  orifice  of  communication  between  the  greater  and  the 
lesser  sacs,  admitting  two  fingers  ;  bounded  above  by  the  cau- 
date lobe  of  the  liver,  below  by  the  first  part  of  the  duodenum 
and  hepatic  artery,  in  front  by  the  right  free  border  of  the 
lesser  omentum,  containing  the  hepatic  artery,  common  bile- 
duct,  and  vena  porti^ ;  behind  by  the  inferior  vena  cava. 

What  are  the  omenta? 

They  are  folds  of  peritoneum  connecting  the  stomach  with 
the  other  viscera,  four  in  number,  viz.  the 

Gasfro-hepatiCy  or  lesser  omentum^^^  extending  between  the 
transverse  fissure  of  the  liver,  lesser  curvature  of  the  stomach, 
and  beginning  of  the  duodenum,  consisting  of  two  layers,  the 
anterior  belonging  to  the  greater,  the  posterior  to  the  lesser 
sac,  which  enfold  at  the  right  free  border  of  the  omentum, 
the  hepatic  artery^  common  hile-dnct^  portal  vein,  lymphatics, 
and  hepatic  nerve-plexus ;  this  border  is  called  the  hepato- 
duodenal ligament. 

The  great  omentum^'*  is  formed  of  four  layers,  two  descend- 
ing, one  from  the  anterior,  the  other  from  the  posterior  wall 
of  the  stomach,  and  uniting  below  to  pass  as  low  as  the  pelvis, 
when  they  ascend  to  the  transverse  colon,  separate  and  em- 
brace this  part  of  the  bowel,  and  pass  to  the  pancreas  as  the 
transverse  mesocolon.  At  about  the  age  of  two  years  the 
two  anterior  layers  of  the  great  omentum  become  adherent 
to  the  transverse  colon  ;  the  part  between  the  stomach  and 
colon  is  then  called  the  gasfro-colic  omentum. 


294  ESSENTIALS  OF  HUMAN   ANATOMY. 

Gasfro-splcuic  omentum  is  a  double  fold  connecting  the  spleen 
with  the  stomach,  contains  the  vasa  brevia  of  the  splenic  artery, 
and  is  continuous  below  with  the  great  omentum. 

What  are  the  mesenteries? 

Double  layers  of  peritoneum  embracing  various  portions  of 
the  intestinal  tube  connecting  them  to  the  vertebral  column  or 
posterior  abdominal  walls  ;  between  the  folds  run  the  vessels 
of  the  part  attached.     They  are  called  the 

Mesentery'^^ ^  mesocecmn,  mesocolon'^'^,  mesorectunij  mesogas- 
trimn. 

What  are  the  ligaments? 

Ligament  is  a  term  applied  to  the  folds  connecting  the  vis- 
cera usually  not  belonging  to  the  intestinal  canal  and  abdom- 
inal walls,  such  as 

The  gastro-2)hrenic  to  the  cardia  of  the  stomach  from  the 
diaphragm. 

The  longitudinal^  two  lateraP"^,  and  coronary  ligaments  of  the 
liver. 

The  vesical,  five  so-called  false  ligaments. 

Two  vesico-uterine'^^,  two  recto-'uterine'^'^  two  hroad  ligaments 
of  the  uterus. 

Suspensory  ligament  of  the  spleen  connecting  this  organ  with 
the  diaphragm  ;  also  the  supporting  ligament  or  phreno-colic. 

Mention  the  viscera  wholly  (M  and  partially  (^)  covered  with 
peritoneum,  and  those  totally  deficient  (^)  in  such  in- 
vestment. 

(1)  The  spleen,  small  intestine^,  cecum,  transverse  colon\  sig- 
moid flexure,  ovaries,  ufervs,  stomach^  and  liver^  practically, 
duodenum  (first  part),  rectum^^  (first  part). 

(2)  Duodenum^  (descending     Rectum  (second  part"), 

and  transverse),  Vagina^'-  (upper  part), 

Ascending  colon,  Bladder ^^  (posterior  surface). 

Descending  colon, 

(3)  Rectum^^  (lower  part),        Pancreas^^, 
Bladder  ^^    (base,    ante-     Kidneys, 

rior  surface).  Suprarenal  capsules, 

Vagina  (lower  and  anterior  portion). 


THE  LARYNX.  295 


ORGANS   OF   VOICE   AND   RESPIRATION. 

The  Larynx. 

What  is  the  larynx^  (Fig.  ]22)? 

The  voice-organ,  formed  of  cartilages  united  by  ligaments, 
the  segments  enjoying  movement  upon  one  another,  which  is 
effected  by  numerous  muscles. 

Mention  the  component  cartilages. 

There  are  nine,  three  being  single  and  three  in  pairs : 

Thyroid  cart ilage^ ^  Two  arytenoid  cartilages'^^ 

Cricoid  cartilage  ^,  Two  cuneiform  cartilages^ 

Epiglottis^  Two  cornicnla  laryngis. 

Describe  the  thyroid  (shield-like)  cartilage. 

It  consists  of  two  alst^^  or  lamellae,  united  at  an  acute  angle 
in  front,  forming  a  vertical  ridge,  whose  more  prominent  upper 
portion  is  called  the  j30Wi7^?7i  Adami^^  or  Adam's  apple;  the 

Inner  surfaces  of  the  alae  are  smooth,  giving  attachment  in 
front,  at  the  receding  angle  formed  by  their  junction,  to  the 
epiglottis,  true  and  false  vocal  cords,  thyro-arytenoid  and  thyro- 
epiglottidean  muscles. 

The  outer  surface  affords  attachment  along  an  oblique  ridge 
to  the  sterno-thyroid  and  thyro-hyoid  muscles,  below  and  behind 
to  the  inferior  constrictor  muscle. 

The  upper  harder  presents  a  deep,  median  notch\  and  is 
slightly  concave  on  either  side. 

The  lower  harder  is  connected  medianly  with  the  cricoid  car- 
tilage by  the  crico-thyroid  membrane,  and  on  each  side  by  the 
cri co-thyroid  muscle. 

The  posterior  borders  are  thick,  rounded,  and  terminate  above 
and  below  on  each  side  in  cornua^  the  two  superior'^  having 
attached  to  their  apices  tlic  lateral  thyro-hyoid  ligaments, 
while  the  inferior*  articulate  internally  by  an  oval  facet  with 
the  cricoid  cartilage  ;  to  this  border  are  also  attached  the  stylo- 
pharyngoiis  nrid  palato-]>haryngeus  muscles. 

Describe  the  cricoid  f ring-like)  cartilage. 

It  is  placed  with  its  narrow  portion'',  annulus,  in  front  and 
the  broad  lamina''  behind,  has  on  (nwh  side  two  articular  fleets, 


296 


ESSENTIALS  OF  HUMAN  ANATOMY. 


BpiglottiS 


one  on  the  upper  margin  behind  for  the  arytenoid  cartilage,  one 
externally  near  the  lower  margin  for  the  inferior  cornu  of  the 
thyroid  cartilage. 

The  upper  harder  gives  attachment  in  front  and  at  the  sides 

to  the  crico-thyroid  mem- 
brane ;  at  the  sides  to  the 
lateral  crico-arytenoid 
muscles  and  inferior  con- 
strictor of  the  pharynx. 

The  loicer  horder  is  hori- 
zontal and  connected  with 
the  first  tracheal  ring  by  a 
fibrous  membrane. 

The  posterior  surface 
presents  a  median  vertical 
ridge ^  the  Jinea  eminens, 
for  the  attachment  of  the 
longitudinal  fibers  of  the 
esophagus,  and  on  each 
side  a  fovea  for  the  at- 
tachment of  the  posterior 
crico-arytenoid  muscle. 


Chr/rt 
Cuneiform. /P  y\ 

0  ^^  „^^   „ 

Jri/lenoicl.  \\/9rMerLOid^iiS\  our/ace 

Ceiwu6eu.i       -yiyifnoi'd  Cxrtiiafreij  ^ase^ 
fiost/cus  ft  ^tztpra^'S  „ 

Cricoid. 

/4iti  ctU.^etfcr 
/4ruCeKOld  Cart. 

/4lfica/ Jacetfor 
jkf.  Coz-nu.  of 
Tft^rotd  Cart, 


Describe  the  two  aryte- 
noid (pitcher-like)  car- 
tilages ^ 

They  are  pyramidal  in 
form,  and  are  placed  on 
the  upper  border  of  the 
cricoid ;  each  has  three 
surfaces  and  three  bor- 
ders, a  base,  and  an  apex. 
Posterior  surface  of  each 
is  triangular  and  concave, 
and  affords  attachment  to 
the  arytenoideus  muscle ; 
Antero-external  surface 
is  convex,  presents  the  fossa  triangularis^  and  has  attached  the 
thyro-arytenoid  muscle  and  false  vocal  cord ; 

Internal  surfaces  face  each  other,  covered   by  mucous  mem- 
brane ; 


Fig.   122.— The  cartilages  of  the  larj-nx ; 
posterior  view. 


THE  LARYNX.  297 

Base  presents  a  concave,  smooth  articular  facet  for  the 
cricoid  cartilage  and  two  prominent  angles  ; 

External  angle  has  attached  to  it  the  posterior  and  lateral 
crico-arytenoid  muscles;  it  is  called  the  muscular  procesa ; 

Anterior  angle,  the  vocal  process,  has  attached  to  it  the  true 
vocal  cord  ; 

Apex  curves  backward  and  inward  and  articulates  with  a  cor- 
niculum  laryngis. 

Describe  the  cornicula  laryngis^  (cartilages  of  Santorini). 

They  are  two  small  conical  cartilaginous  nodules  surmount- 
ing the  apices  of  the  arytenoid  cartilages,  affording  attachment 
to  the  aryteno-epiglottic  folds. 

Describe  the  cuneiform  cartilages^  (cartilages  of  Wrisberg). 
They  are  elongated  cartilages  contained  in  the  free  borders 
of  the  aryteno-epiglottic  folds  just  in  front  of  the  cornicula. 

Describe  the  epiglottis '^ 

It  is  a  thin,  leaf-shaped  lamella  of  fihro-cartilage,  attached 
by  its  apex  to  the  reentering  angle  of  the  thyroid  cartilage 
just  below  the  median  notch  ;  it  lies  at  the  base  of  the  tongue, 
in  front  of  the  upper  opening  of  the  larynx,  and  during  deglu- 
tition shuts  like  a  lid  over  the  laryngeal  orifice.     Its 

Base  is  free,  rounded,  curving  forward  toward  the  base  of 
the  tongue. 

Apex  is  attached  to  the  receding  angle  of  the  thyroid  by 
the  tliyro-epi glottic  ligament. 

Anterior  surface  is  covered  with  mucous  membrane  reflected 
on  to  the  sides  and  base  of  the  tongue,  forming  three  glosso- 
epi glottic  folds ;  externally  on  each  side  maybe  a  pliaryngo- 
epiglof  tic  fold;  a  median  elastic  structure  connects  this  surface 
with  the  posterior  surface  of  the  hyoid  body,  the  hyo-epiglottic 
ligament. 

Posterior  surface  shuts  down  over  the  laryngeal  opening 
during  deglutition  ;  it  presents  a  prominence  called  the  tubercle 
or  cushion. 

Lateral  margins  give  attachment  to  the  aryteno-epiglottic 
folds. 

How  are  the  ligaments  of  the  larynx  divided  ? 

Into  extrinsic,  or  those  connecting  the  tliyroid  cartilage  and 


298  ESSENTIALS  OF  HUMAN  ANATOMY. 

epiglottis  with  the  hyoid  bone,  and  cricoid  cartilage  with  the 
trachea ;  and  intrinsic,  those  binding  the  various  cartilages 
together. 

Name  the  extrinsic  ligaments. 

TInjro-lujoid  mcmhrane,  middle  and  tico  lateral  thyro-hyoid 
ligaments,  containing  a  small  cartilaginous  or  bony  nodule, 
cartilago  triticea ;  thyro-  and  liyo-epi glottic  ligaments,  crico- 
tracheal  membrane. 

Name  the  intrinsic  ligaments. 

The  intrinsic  articulations  of  the  larynx  are  four :  crico-tliy- 
roid  below,  crico-arytenoid  above,  each  possessing  a  ligamentous 
capsule  and  synovial  sac.  The  strengthening  bands  of  the 
crico-thyroid  joint  are  the  anterior,  j^ostero-sujwrior,  and  postero- 
inferior  herato-cricoid  ligaments.  The  strengthening  band  of 
the  crico-arytenoid  joint  is  the  posterior  crico-arytenoid  passing 
from  below,  upward  and  outward.  Other  ligaments  are  the 
two  superior  and  two  inferior  thyro-arytenoid  and  crico-thyroid 
membrane. 

What  are  the  vocal  cords? 

The  superior  or  false  vocal  cords,  on  each  side,  are  two  folds 
of  mucous  membrane  enclosing  the  superior  thyro-arytenoid 
ligaments  composed  of  elastic  tissue,  stretching  between  the 
angle  of  the  thyroid  cartilage  below  the  epiglottis  and  anterior 
surfaces  of  the  arytenoid  cartilages;  the  lower  margin  forms 
the  upper  free  crescentic  margin  of  the  ventricle  of  the  larynx. 

The  true  or  inferior  vocal  cords  are  two  strong,  yellow  elas- 
tic fibrous  tissue  bands,  the  inferior  thyro-arytenoid  ligaments, 
covered  by  thin,  tightly   adherent  mucous  membrane,  which 
pass  from  the  receding  angle  of  the  thyroid  to  the  anterior 
angles  of  the  arytenoid  cartilages,  the  upper  border  forming 
the  lower  margin  of  the  ventricle  of  the  larynx,  the  lower  con- 
tinuous with  the  lateral  portion  of  the  crico-thyroid  membrane 
each  has  the  thyro-arytenoid  muscle  lying  parallel  externally 
these  cords  or  membranes  produce  sound  by  their  vibrations 
the  false  cords  do  not,  although  they  indirectly  influence  vocal- 
ization. 

What  are  the  glottis  and  the  rima  glottidis? 

The  glottis  is  the  narrow  triangular  interval  between  the  true 


THE  LARYNX.  299 

vocal  cords  in  front,  and  between  the  arytenoids  and  the  vocal 
processes  behind  ;  the  rima  is  the  boundary  of  the  space. 

Describe  the  ventricle  of  the  larynx. 

It  consists  of  an  oval  depression  or  simm  on  each  side,  be- 
tween the  true  and  the  false  vocal  cords  leading  upward,  ex- 
ternal to  the  superior  cord,  into  a  cecal  pouch,  the  sacculus 
laryngis^  or  laryngeal  pouch. 

Describe  the  sacculus  laryngis. 

It  is  a  slightly  curved  conical  membranous  sac,  situated  be- 
tween the  inner  surface  of  the  thyroid  cartilage  and  false  vocal 
cord  on  each  side  ;  internally  lined  with  mucous  membrane, 
perforated  by  orifices  of  the  ducts  of  sixty  to  seventy  follicu- 
lar glands  lying  in  the  submucous  tissue ;  it  is  strengthened 
externally  by  a  fibrous  capsule  continuous  below  with  the  su- 
perior thyro-arytenoid  ligament,  and  has  its  inner  (laryngeal) 
surface  covered  by  the  inferior  aryteno-epiglottideus,  and  its 
external  by  the  tliyro-epiglottideus  and  thyro-arytenoid  mus- 
cles, which  compress  the  sacculus ;  the  pouch  is  probably  a 
remnant,  and  the  function  is  resonance.  ' 

What  kind  of  epithelium  has  the  mucous  membrane  ? 

Above  the  false  vocal  cords  squamous  epithelium  is  found, 
except  in  front,  where  it  is  covered  by  ciliated  columnar  cells 
as  high  as  the  middle  of  the  epiglottis  ;  below  the  false  cords 
only  ciliated  columnar  epithelium  is  found. 

Describe  the  muscles  of  the  larynx  and  epiglottis. 

Crico-thyroideus  -  (Fig.  123):  origin^  hnver  border  of  the 
thyroid  and  anterior  border  of  the  lower  cornu  ;  insertion,  tri- 
angular into  the  antero-lateral  surface  of  the  cricoid  cartilage  ; 
action,  increases  tension  of  the  vocal  cords  by  lifting  the  cricoid 
cartilage  upward  ;  nerve,  superior  laryngeal. 

Crico-arytenoideus  posticus :  origin,  lateral  half  of  the  poste- 
rior surf;ic(;  of  the  cric(jid  ;  insertion,  outer  angle  of  the  base 
of  the  arytenoid  cartilage  ;  action,  the  two  muscles  by  rotating 
the  arytenoid  cartilages  outward  open  the  glottis  and  tighten 
the  cords;  nerve,  recurrent  laryngeal. 

Crico-arytenoideus  lateralis:  origin,  upper  border  of  the  side 
of  the  cricoid ;  insertion,  outer  angle  of  Lhe  base  of  the  aryte- 


300  ESSENTIALS  OF  HUMAN   ANATOMY. 

noid  ;  action^  by  rotating  the  arytenoid  inward  it  closes  the 
glottis ;    verve,  recurrent  laryngeal. 

Thyro-arytenoideus :  cyrigin,  lower  half  of  the  receding  angle 
of  the  thyroid  and  crico-thyroid  membrane  ;  wsei-tion,  by  an 
outer  and  an  inuer  port  ion  into  the  base,  two  angles,  anterior  sur- 
face of  the  arytenoid,  and  into  both  vocal  cords  ;  action,  relaxes 
the  vocal  cords  and  compresses  the  sacculus  laryngis ;  nerve, 
as   above. 

Arytenoideus  has  a  firinsverse  and  two  oblique  portions  ;  passes 
from  the  back  surface  and  outer  border  of  one  arytenoid  to  the 
same  part  of  the  other  cartilage  ;  action,  approximates  the  ary- 
tenoids closing  the  back  of  the  glottis ;  nerves,  superior  and 
recurrent   laryngeal. 

Kerato-cricoideus,  near  the  posterior  crico-arytenoid  :  origin, 
from  the  lower  border  of  the  cricoid  cartilage  ;  insertion,  inferior 
cornu  of  the  thvroid  cartilage ;  action,  possiblv  steadies  one 
cartilage  upon  the  other;  only  occasionally  found,  and  usually 
on  one  side. 

Triticeo-glossus :  origin,  cartilage  of  the  same  name  in  the 
lateral  thyro-hyoid  ligament;  insei't ion,  tongue  v^ith.  the  hj^o- 
glossus  muscle  ;  occurs  on  one  or  both  sides  ;  action,  unknown. 

Describe  the  muscles  of  the  epiglottis. 

Thyro-epiglottideus :  origin,  inner  surface  of  the  thyroid  carti- 
lage ;  insertion,  ar3"teno-epiglottic  fold,  margin  of  the  epiglottis, 
outer  surface  of  the  sacculus  laryngis  ;  this  may  be  described 
as  a  part  of  the  thyro-arytenoid  muscle;  action,  depresses  the 
epiglottis  ;   nerve,  recurrent  laryngeal. 

Arjrteno-epiglottideus  superior:  origin,  apex  of  the  arytenoid 
cartilage;  insertion,  aryteno-epiglottic  fold;  action,  narrows 
the  upper  laryngeal   orifice  ;    nerve,  recurrent  laryngeal. 

Aryteno-epiglottideus  inferior:  origin,  arytenoid  cartilage  above 
the  superior  vocal  cord  ;  insertion,  part  of  the  epiglottis  and 
inner  surface  of  the  laryngeal  pouch  ;  action,  compresses  the 
sacculus  laryngis ;   nerve,  recurrent  laryngeal. 

Mention  the  arteries  and  veins  of  the  larynx. 

The  arteries  are  laryngeal  branches  of  the  superior  and  infe- 
rior thyroids,  and  dorsalis  linguae  for  the  epiglottis. 

The  veins  empty  into  the  superior,  middle,  and  inferior  thy- 
roids, and  the  lingual. 


THE  TRACHEA  AND  BRONCHI.        301 

What  nerves  supply  the  larynx? 

The  superior^  and  inferior  or  recurrent  laryngeal^  branches  of 
the  pneumogastrie,  the  former  derived  largely  from  the  acces- 
sory part  of  the  spinal  accessory  and  superior  cardiac  sympa- 
thetic nerves. 

Superior  laryngeal  is  chiefly  a  nerve  of  sensation,  supplying 
the  laryngeal  mucous  membrane  and  arytenoid  muscles  by  its 
internal  laryngeal  branch,  after  piercing  the  thyro-hyoid  mem- 
brane ;  and  the  crico-thyroid  muscle  by  its  external  laryngeal 
branch ;   the 

Recurrent  laryngeal  is  the  motor  nerve  supplying  all  the  lar- 
yngeal muscles  except  the  crico-thyroicl ;  the  right  nerve  de- 
scends in  the  neck  to  pass  from  before  backward  under  the 
subclavian  artery  ;  the  left  winds  in  the  same  direction  under 
the  aortic  arch,  and  both  nerves  ascend  in  the  groove  between 
the  trachea  and  esophagus  to  their  distribution,  giving  off  in 
their  course  cardiac,  esophageal,  tracheal,  and  pharyngeal 
branches,  and  anastomosing  with  the  superior  laryngeal 
nerves. 

The  Trachea  and  Bronchi. 

What  is  the  trachea^  (Fig.  123)? 

It  is  a  membranous,  cylindrical  air-tube,  flattened  posteriorly, 
of  a  transverse  diameter  of  three-quarters  to  one  inch  (2  to  2^- 
cm.),  length,  four  and  one-half  inches  (10  to  11  cm.),  extend- 
ing from  the  lower  part  of  the  larynx  (corresponding  to  the 
sixth  cervical  vertebra)  to  the  disk  between  the  fourth  and 
fifth  thoracic  vertebrae,  where  it  bifurcates  to  form  the  right  and 
left  bronchus;  it  is  composed  of  sixteen  to  twenty  imperfect 
cartilaginous  rings  surrounding  two-thirds  of  the  cylinder,  en- 
closed in  a  double  elastic  fibrous  membrane  connecting  the 
rings  with  one  another,  while  the  space  behind  has,  within  the 
membrane,  a  layer  of  longitudinal  and  another  of  transverse 
unstriped  muscular  fibers,  the  transverse  being  called  the  tra- 
cJiealia  munch' ;  the  last  ring,  by  a  triangular  hooked  process 
curving  backward  between  the  bronchi,  forms  two  imperfect 
rings  on  either  side  for  the  right  and  left  bronchus ;  the  lining 
mucous  membraiK!  contains  much  lyni})hoid  tissue  and  elastic 
fibers,  and  is  covered  by  several  layers  of  epithelium,  the  most 
superficial  is  columnar  ciliated;  mucous  glands  Vio  in  the  poste- 
rior part  of  the  fibrous  layer. 


302  ESSENTIALS  OF  HUMAN   ANATOMY. 

Give  the  relations  of  the  trachea  in  the  neck. 

It  is  covered  in  front  from  above  downward  by 
Anastomoses  between  the  an-     Posteriorly^  it  lies  upon  the 

terior  jugular  veins,  Esophagus, 

Isthmus  of  the  thyroid  gland.     Laterally^  are 
Inferior  thyroid  veins,  The  common  carotid  arteries'*, 

Arteria  thyroidea  iraa,  Lobes  of  the  thyroid  gland, 

Cervical  fascia,  Inferior  thyroid  arteries, 

Sterno-hyoid  muscle,  Recurrent  laryngeal  nerves. 

Sterno-thyroid  muscle. 

Describe  its  relations  in  the  thorax. 

It  is  covered  from  before  backward  by  the 
Manubrium  of  the  sternum,         Sterno-hyoid  muscle, 
Remains  of  the  thymus  gland,     Sterno-thyroid  muscle, 
Left  innominate  vein,  Posteriorly^  lies  the 

Arch  of  the  aorta.  Esophagus, 

Innominate  artery,  Laterally^  on  each  side,  the 

Left  carotid  artery  ^^,  Pneumogastric      nerve      and 

Deep  cardiac  plexus,  pleura. 

What  are  the  bronchi? 

Two  tubes,  structurally  like  the  trachea,  extending  from  its 
bifurcation  into  the  lungs,  dividing  and  subdiving  to  form  the 
bronchial  tubes,  in  whose  walls  only  scattered  cartilaginous 
plates  exist  until  the  diameter  .2  mm.  (y^-g-  of  an  inch)  is  reached, 
when  they  become  wholly  membranous,  while  the  muscular  coat 
and  the  elastic  fibrous  coat  then  form  a  continuous  circular  layer 
around  the  smallest  tubes ;  the  mucous  membrane  is  covered 
with  ciliated  columnar  epithelium  ;  the  right  bronchus  is  wider, 
shorter,  and  more  horizontal  than  the  left ;  it  is  one  inch  long 
(2.4:  cm.),  diameter,  2.2  cm.,  has  five  or  six  rings  ;  the  left 
bronchus  is  smaller,  more  oblique,  and  longer,  two  inches  long 
(5.1  cm.),  diameter,  2  cm.,  and  has  nine  or  ten  rings. 

Describe  the  relations  of  each  bronchus. 

The  right  begins  opposite  the  fourth  thoracic  disk,  enters  the 
lung  opposite  the  fifth  thoracic  vertebra,  lying  behind  the  supe- 
rior vena  cava  and  right  auricle  of  the  heart,  having  the  right 
pulmonary  artery  at  first  below,  then  anterior  to  it,  and  the 
vena  azygos  major  arching  over  it  from  behind. 


THE  LUNGS.  303 

The  left  bronchus^  commencing  at  the  same  point  as  the  right, 

passes  in  front  of  the  esophagus,  thoracic  duct,  and  descending 
aorta  beneath  the  aortic  arch,  the  left  pulmonary  artery  lying 
at  first  above,  then  in  front  of  it  to  enter  the  lung  opposite 
the  sixth  thoracic  vertebra. 

The  left  bronchus  is  Ivj parte  rial ;  the  right  gives  off  the 
eparterial  branch,  then  each  gives  four  ventral  and  four  dorsal 
branches  ;  the  right  has  in  addition  an  azygos  branch.  On  the 
right  the  eparterial  bronchus  goes  to  the  upper  lobe,  the  first 
ventral  to  the  middle  lobe,  the  three  lower  ventral  and  all  the 
dorsal  to  the  lower  lobe.  On  the  left  side  the  hyparterial 
bronchus,  which  is  the  first  ventral,  goes  to  the  upper  lobe  ; 
the  other  ventral  and  all  the  dorsal  pass  to  the  lower  lobe. 

What  vessels  and  nerves  supply  the  trachea  and  bronchi  ? 

The  arteries  are  tracheal  branches  of  the  inferior  thyroid 
arteries  and  the  bronchials  from  the  aorta  ;  the 

Veins  empty  into  the  thyroid  plexus  and  bronchial  veins. 

Lympliaticii  empty  into  the  mediastinal  glands. 

Nerves  are  branches  from  the  pneumogastric,  recurrent 
laryngeal,  and    sympathetic. 

The  Lungs. 

Describe  them  (Fig.  123). 

They  are  the  two  organs  of  respiration,  occupying  the  greater 
part  of  the  thoracic  cavity,  separated  by  the  heart  and  other 
contents  of  the  mediastinum,  covered  by  the  pleura?,  of  a 
specific  gravity  of  0.34.5  to  0.746,  the  right  weighing  twenty- 
two  ounces,  the  left,  twenty;  in  the  ratio  of  11  to  10.  They 
are  pinkish-white  at  birth,  but  irregularly  marked  by  slate- 
colored  patches  as  age  advances  from  the  deposit  of  carbona- 
ceous matter  in  the  lung-tissue  (a  condition  called  anthracosis) ; 
they  are  divided  into  lobes,  the  right  lung  having  three  *,  ^,  *, 
the  left  two^^;  each  lung  has  an  apex,  four  surfaces,  and  two 
borders. 

Apex,  extending  into  the  root  of  the  neck  above  the  first  rib, 
about  one  to  one  and  a  half  inches,  where  it  is  in  relation  with 
the  first  and  second  part  of  the  subclavian  artery,  separated 
by  pleura  ;  the 

Bfme  or  phrenic  surface  is  broad  and  concave,  resting  upon 
the  diaphragm,  its  thin  margins  extending  lower  down  exter- 
nally and  behind  than  in  front ;  the 


304 


ESSENTIALS  OF  HUMAN   ANATOMY. 


External  or  costal  surface  is  smooth,  convex,  miirked  by  the 
interlobular  fissures,  and  conforms  to  the  shape  of  the  thorax. 

Inner  or  mediastinal  surface  is  concave,  and  the  left  lung 
presents  a  depression  in  front  for  the  heart ;  above  and  behind 


Fig.  123— Anterior  view  of  the  larynx,  trachea,  lungs,  and  heart  (Leidy). 


the  center  each  presents  the  hilum  pulmonis,  for  the  attach- 
ment of  the  root  of  the  lung ;  the 

Root"^^  consists  of  a  bronchus,  pulmonary  and  bronchial  arte- 
ries, pulmonary  and  bronchial  veins  and  lymphatics,  bronchial 
glands,  anterior  and  posterior  pulmonary  plexuses,  all  con- 
nected by  areolar  tissue  and  enclosed  by  pleura  ;  in  front  of 
each  lies  the  phrenic  nerve  and  anterior  pulmonary  plexus; 
behind,  the  pneumogastric  nerve  and  posterior  pulmonary 
plexus. 


THE  LUNGS. 


305 


In  what  order  are  these  various  structures  arranged? 

From  before  backward  ; 

Both  lungs  : 

Pulmonary  veins, 
Pulmonary  artery, 
Bronchus,  etc.  ) 

From  above  downward  ; 


may  be  recalled  by  letters, 

y.  A,  B. 


Right  luns: : 


Bronchus,  ^       ,     • 

T->   I  ^  f  anterior 

Pulmonary  artery,  V 

Pulmonary  veins,  j 


■ 

B 

A    I 
V 


posterior 


Left  lung  : 

Pulmonary  artery, 
Bronchus, 
Pulmonary  veins. 


anterior 


A 

B 
V 


posterior 


The  j)osterior  surface,  often  described  as  the  border,  is  thick, 
rounded,  and  fits  into  the  sulcus  pulmonalis  on  each  side  of  the 
vertebral  column  ;  this  surface  on  the  left  lung  shows  a  groove 
for  the  thoracic  aorta,  on  the  right  lung  a  groove  for  the  vena 
azygos  major.  A  low  ridge  lies  parallel  to  and  behind  the 
hiluin,  and  anterior  to  the  groove  ;  this  may  be  called  the 
jyosterior  border  (Joessel).  The  anterior  border  is  sharp  and 
thin,  overlaps  the  pericardium,  and  the  left  one  presents  a  notch 
or  cardiac  incisure.  The  inferior  border  is  the  sharp  margin  sur- 
rounding the  base  of  the  lung,  the  greater  part  of  which  dips  into 
a  pleural  recess  above  the  costal  attachments  of  the  diaphragm. 

The  left  lung  is  divided  by  the  left  interlobular  incisure  or 
fssure  into  two  lobes  ;  this  fissure  passes  from  the  upper  and 
back  part  of*  the  hilum,  upward  and  backward  through  the 
posterior  surface,  descends  through  the  outer  surface  to  the 
inferior  border,  a  thumb's  breadth  from  the  anterior  border, 
then  passes  up  through  the  inner  surface  to  the  lower  part  of 
the  hilum.  The  linffual  lobule  is  included  between  this  and  the 
cardiac  incisure.  The  right  lung  has  two  fissures  and  three 
hjbes  ;  the  rirfht  interbtbubir  incisure  starts  like  the  left  one,  is 
more  vertical  and  reaches  the  inferior  )>order  a  hand's  breadth 
from  the  anterior  border  and  passes  up  through  the  inner  sur- 
20 


306 


ESSENTIALS  OF  HUMAN   ANATOMY. 


face  to  the  hilum  ;  this  main  fissure  separates  the  lower  lobe 
from  the  upper  and  middle  lobes.  An  additional  fissure  extends 
from  about  the  center  of  the  above  nearly  horizontally  forward 


Upper  lohr 


Upper  lobe 


Sinus 
phrenico- 
co^tali 


Sinus  me- 
'ladino- 
costalis 

J II  ci  sura 

'iiterlob. 

sinistra 

Incis.  car- 

diaca 
Siniisperi- 
mrdiaco- 
costdlis 

Lob.  lin- 
giialis 

L  wer  lobe 


Line <  inainmilUwis 

Ltnea  parasternalis 

Linea  sternal  is 


Liiiea  mammillaris 
Linea  parastenudis 


J'lace  where  pericardium  is  in  direct  con- 
tact with  sternum. 


Fig.  124.— Relations  of  the  lungs  to  the  anterior  chest-wall  (after  Joessel). 

to  the  anterior  border  and  thence  on  the  inner  surface  to  the 
hilum. 

Describe  the  structure  of  the  lungs. 

They  have  externally  a  serous  coat,  a  subserous  areolar  tissue 


THE  LUNGS. 


307 


penetrating  between  the  lobules ;  lung-tissue  is  composed  of 
tlie  pulmonary  substance  or  parenchyma,  which  is  formed  of  an 
aggregation  of  lohules^  each  composed  of  a  terminal  bronchial 
tube  with  its  air-cells,  and  ramifications  of  pulmonary  and 
bronchial  vessels,  lymphatics,  and  nerves,  thus  forming  a  lung 
in  miniature  ;  they  are  pyramidal  and  large  upon  the  surface, 
smaller  and  irregular  in  the  interior ;  the  ahroli,  or  air-cells, 
are  small  polyhedral  alveolar  recesses  measuring  about  0.25 
mni.  (-j-^o  inch)  in  diameter.  The  bronchi  divide  bipinnately 
into  smaller  and  smaller  bronchioles  or  lohulnr  hronchial  tuhes 
which  never  anastomose;  when  the  diameter  is  reduced  to 
about  0.2  mm.  their  walls  and  mucous  membrane  change,  little 
alveoli  appear  on  a  wall  and  finally  cover  it.  At  its  end  in  a 
lobule,  it  divides  into  parts  named  from  the  plan  of  a  Roman 
house  (Fig.  125);  first  the  atrium  (entry)  or  alveolar  jx^^^saye, 


Fig  P5  —Diagrammatic  representation  of  the  termination  of  a  bronchial 
tube  in  a  group  of  infundibula:  iJ,  bronchial  tube  ;  Zi?,  bronchiole  ;  ^.atnum; 
I,  infundibulum  ;  C,  alveoli. 

from  which  arc  given  off  blind  pouches,  infamUhnla,  every- 
where closely  beset  with  air-cells  ;  they  are  separated  from  one 
another  by  delicate  membranous  septa,  between  the  layers  of 
which  lies  the  plexus  formed  by  the  pulmonary  artery,  thus 
exposing  the  blood  to  air  on  two  surfaces;  they  are  lined  with 
a  layer  of  squamous  epithelium. 

What  are  the  vessels  and  nerves  of  the  lungs  ? 

They  receive  blood  by  the  bronchial  arteries  for  their  own 
nutrition,  and  venous  blood  by  the  pulmonary  artery  for  aera- 
tion— /.  r.  absorption  of  oxygen  and  emission  of  carbonic  di- 
oxid  ;  the  vessels  are: 


308  ESSENTIALS  OF  HUMAN   ANATOMY. 

Bronchud  arteries,  branches  of  the  aorta.  Pnhnonari/  artery, 
from  the  right  side  of  the  heart.  The  Itranchial  vein  empties 
on  the  right  side  into  the  vena  azygos  major,  on  the  left  into 
the  superior  intercostal  vein.  The  pnlinoiiari/  veins,  four  in  num- 
ber, carry  arterial  blood  to  the  left  auricle. 

Lymphatics,  a  superficial  and  a  deep  set,  empty  into  the 
bronchial  glands ; 

Nerves  are  derived  from  the  anterior  and  posterior  pulmo- 
nary plexuses,  formed  chiefly  by  branches  from  the  sympa- 
thetic and  pneumogastric  nerves. 

The  Pleurae. 

Describe  the  pleura. 

They  are  two  closed  serous  sacs,  not  communicating  with 
each  other  and  wholly  separated  except  anteriorly,  leaving  a 
space  called  the  mediastinum.  The  right  sac  is  shorter  and 
wider  than  the  left  one. 

The  membrane  reflected  over  the  lungs  to  the  roots  is  the 
visceral  layer,  or  pleura  pidmonalis  ;  the  part  continuous  with 
this  and  lining  the  inner  surface  of  the  thorax  is  the  parietal 
layer,  named,  according  to  XoddXion,  pleura  costalis,  Siho  phrenic, 
mediastinal,  cervical,  d^ndi  pericardial  pleura  ;  between  the  pari- 
etal and  visceral  layers  is  the  pleur(d  cavity,  which  does  not 
exist  unless  made  artificially  or  by  disease,  as  the  two  layers 
lie  in  contact.  Descending  vertically  along  the  inner  surface 
of  the  lung  from  its  root  to  the  diaphragm  is  a  double  fold  of 
pleura,  the  broad  pulmonary  ligament  {ligamentum  latum  pul- 
monis^. 

In  certain  regions  two  parietal  portions  of  the  pleura  may 
form  a  sharp  angle  or  recess,  into  which  the  margin  of  the  lung 
may  or  may  not  enter  ;  it  is  a  region  between  the  extreme  lung- 
limit  and  extreme  pleural  limit,  called  pleural  sinus,  or  com- 
plemental  space;  sinus  phrenico-costalis,  or  costo-phrenic,  is  the 
angle  where  the  costal  and  phrenic  pleurae  meet ;  sinus  niedias- 
tino-phrenicus  is  antero-posterior  on  the  upper  surface  of  the 
diaphragm,  near  the  middle  line,  and  most  marked  where  the 
pericardial  pleura  meets  the  phrenic;  sinus  mediastino-costalis 
is  more  or  less  vertical,  is  anterior  and  behind  the  sternum  ; 
sinus  pericardiaco-costalis  is  between  the  pulmonary  and  pleural 
limits  on  the  left  side  between  the  fourth  and  sixth  costal  car- 
tilages, where  the  heart  is  not  covered  by  the  lung. 


THE  PLEURA.  309 

Describe  the  mediastinum. 

It  is  the  median  space  between  the  two  pleural  sacs,  extend- 
ing from  the  sternum  to  the  vertebral  column,  containing  all 
the  thoracic  viscera  except  the  lungs. 

It  is  divided  into  four  parts,  regarding  the  pericardium  as  a 
center:  iha  middle  medidsfu nun  contains  the  pericardium  and 
contents ;  the  anterior  is  in  front  of  it,  posterior  behind,  and 
superior  above. 

The  superior  mediastinum  is  bounded  below  by  a  plane 
passing  through  the  junction  of  the  manubrium  and  gladiolus 
to  the  lower  border  of  the  fourth  thoracic  vertebra; "in  front 
of  it  are  the  manubrium  and  origins  of  the  sterno-hyoid  and 
sterno-thyroid  muscles ;  behind  are  the  four  upper  thoracic 
vertebrae  and  part  of  the  longus  colli  muscles.  It  contains  the 
trachea,  esophagus,  thoracic  duct,  arch  of  the  aorta,  innomi- 
nate artery,  thoracic  parts  of  the  left  common  carotid  and  left 
subclavian  arteries,  innominate  vein,  left  superior  intercostal 
vein,  upper  half  of  the  superior  vena  cava,  phrenic,  pneumo- 
gastric,  left  recurrent,  and  cardiac  nerves,  lymphatic  glands, 
and  remains  of  the  thymus  gland. 

The  anterior  mediastimim^  placed  obliquely,  narrow  above,  is 
bounded  in  front  by  the  gladiolus,  triangularis  sterni  muscle, 
sometimes  by  the  fifth,  sixth,  or  seventh  left  costal  cartilage; 
behind  is  the  pericardium.  Its  contents  are  areolar  tissue, 
lymphatic  vessels,  and  two  or  three  lymphatic  glands. 

The  middle  mediastiinrni  contains  the  pericardium,  heart, 
ascending  aorta,  pulmonary  artery,  lower  half  of  the  superior 
vena  cava,  arch  of  the  vena  azygos  major,  phrenic  nerves  and 
attendant  arteries,  bifurcation  of  the  trachea,  roots  of  the 
lungs,  and  the  bronchial  glands. 

The  posterior  mediastimim  lies  between  the  pericardium, 
roots  of  the  lungs  and  diaphragm  in  front,  and  the  thoracic 
vertebral  column  behind,  beginning  at  the  fourth  vertebra ; 
it  contains  the  thoracic  aorta,  esophagus,  pneumogastric  and 
splanchnic  nerves,  azygos  veins,  some  right  intercostal  arteries, 
thoracic  duct,  and  lymphatic  glands. 

Describe  the  topographical  anatomy  of  the  lungs  and  pleurae. 
The  surface  of  the  chest  is  marked  off  by  certain  transverse 
and  vertical  lines.     Three  levels  are  used  for  taking  measure- 
ments of  circumferences  of  the  chest-wall  :   (1)  at  level  of  the 


310  ESSENTIALS  OF  HUMAN   ANATOMY. 

highest  points  of  the  axillae;  (2)  at  level  of  the  nipples;  (3)  at 
level  of  the  sterno-xiphoid  articulation  (Fig.  124).  Vertical 
lines  are  (1)  the  Unea  mediana,  ov  mid-sternal  line;  (2)  the 
linea  steriialis^  along  each  edge  of  the  sternum  ;  (3)  the  linea 
mammi/larix,  or  pdpiUftris,  through  the  nipple;  (4)  the  linea 
parasternalis,  midway  between  sternal  and  mammillary  lines  ; 
(5)  the  Unea  axWaris  to  the  highest  point  of  the  axilla,  also 
the  anterior  and  jioaferior  axiU<iri/  lines  from  the  anterior  and 
posterior  folds  respectively  ;  (6)  the  linea  scapvlaris,  drawn 
through  the  inferior  angle  of  the  scapula  ;  (7)  the  mid-dorsal 
or  vertebral  line,  drawn  through  the  spinous  processes  of  the 
vertebrae;  (8)  the  linea  sterno-costalis  (costoclavicular  line), 
drawn  from  a  sternoclavicular  articulation  to  the  tip  of  the 
eleventh  rib  on  the  same  side. 

3Ieasurements  of  the  Tliorax  (Joessel). 

Perimeters. 
Male.  Female. 

At  the  level  of  the  highest  points  of  the  axilla- .  89. o2  cm.         81 .90  cm. 

At  the  level  of  the  nip})les 86.64  cm.         81.00  cm. 

At  the  level  of  the  sterno-xiphoid  articulation  .  81.88  cm.         78.00  cm. 

Diameters:  transverse,  through  the  eighth  or  ninth  ribs,  28 
cm. ;  antero-posterior ,  at  the  base  of  the  ensiform  process,  20 
cm. ;  vertical  along  the  posterior  wall,  31.5  cm. ;  vertical  along 
the  anterior  wall,  15.5  cm. 

The  internal  sagittal  diameter  is  1  cm.  more  than  half  the 
external,  or  11  cm. ;  the  internal  transverse  diameter  is  \^  to 
2  cm.  less  than  the  external. 

Pleimd  limits :  anteriorly  the  right  and  the  left  pleural  mar- 
gins pass  from  the  sterno-clavicular  articulations  and  meet  be- 
hind the  sternum  at  the  junction  of  the  manubrium  and  gla- 
diolus ;  from  the  second  to  the  fourth  or  fifth  cartilages  they  are 
in  contact  or  overlap ;  here  the  left  layer  usually  deviates,  and 
at  the  level  of  the  sternal  end  of  the  fifth  costal  cartilage  is  1.5 
cm.,  at  the  sixth  2  cm.,  and  at  the  seventh  3.5  cm.,  external 
to  the  left  margin  of  the  sternum  ;  on  the  right  side  it  descends 
to  the  level  of  the  sixth  costal  cartilage  in  the  midline  ; 

At  the  sternal  line  the  pleura  on  the  right  side  crosses  the 
upper  margin  of  the  seventh  costal  cartilage  ; 

At  the  parasternal  line  it  crosses  the  middle  of  the  seventh 
costal   cartilage ; 


THE  PLEURA.  311 

At  the  mammiUari/  line  it  crosses  tlie  lower  margin  of  the 
seventh  costal  cartilage  ; 

At  the  middxilhiry  line  it  crosses  the  ninth  rib  ; 

In  the  vertebral  region  it  reaches  the  twelfth  rib  or  the  trans- 
verse process  of  the  first  lumbar  vertebra.  The  limit  on  the  left 
side  may  be  a  little  lower  than  on  the  right,  but  clinically  there 
is  no  difference. 

Surface  form  of  the  lungs  :  the  anterior  borders  of  the  lungs 
approach  from  the  sterno-clavicular  articulations,  and  almost 
meet  behind  the  sternum  on  a  level  with  the  second  costal 
cartilages  ;  thence  they  descend  together  to  the  level  of  the 
fourth  cartilages ;  the  right  margin  passes  nearly  straight 
behind  the  sternum  to  the  level  of  the  sixth  chondro-sternal 
articulation.     The  lowest  lung-limits  on  the  right  side  are : 

At  the  sternal  line,  upper  margin  of  the  sixth  costal  carti- 
lage; 

At  i\\Q  parasternal  line,  lower  margin  of  the  sixth  costal  car- 
tilage ; 

At  the  mammillary  line,  upper  margin  of  the  seventh  rib  ; 

At  the  midaxillary  line,  lower  margin  of  the  seventh  rib ; 

At  the  scapular  line,  the  limit  crosses  the  ninth  rib  ; 

In  the  vertehral  region,  it  reaches  the  eleventh  rib. 

At  the  fourth  costal  cartilage  the  anterior  margin  of  the  left 
hnig  slopes  outward  under  its  lower  edge,  crosses  behind  the 
fifth  cartilage,  and  reaches  a  spot  in  the  fifth  space  correspond- 
ing to  the  apex  of  the  heart ;  the  margin  then  curves  inward, 
but  not  to  reach  the  sternal  line  again.  This  space  uncovered 
by  the  lung  is  the  "  area  of  superficial  cardiac  dulness." 

The  lower  edge  of  the  Ungual  lobule  touches  the  sixth  costal 
cartilage  in  the  parasternal  line  and  then  the  lowest  lung- 
limit  runs,  as  on  the  right  side,  to  the  eleventh  rib.  The 
height  of  the  costo-phrenic  sinus  in  quiet  respiration  is  2  cm. 
ffour-fifths  of  an  inch)  at  the  sternal,  parasternal,  and  mam- 
millary lines,  6  cm.  at  the  axillary,  and  2.5  cm.  in  the  vertebral 
region. 

The  line  of  projection  of  the  left  intrrhthuhir  incisure  on  the 
chest-wall  begins  opposite  the  inner  end  of  the  spine  of  the 
scapula  on  the  level  of  the  spinous  process  of  the  third  thoracic 
vertebra,  then  passes  obliquely  downward  and  forward  to  the 
outer  end  of  the  sixth  costal  cartilage.  This  marks  the  separa- 
tion between  the  two  lobes  of  the  left  lung. 


312  ESSENTIALS  OF  HUMAN   ANATOMY. 

The  riglit  infrrJoJnilnr  incisure  starts  on  the  same  level  as 
that  which  marked  the  left  one,  descends  obliquely  over  the 
posterior  axillary  line,  crosses  the  inferior  angle  of  the  scapula, 
and  reaches  the  inferior  border  of  the  lung  at  the  mammillary 
line  on  the  seventh  rib. 

The  middle  incisure  starts  at  the  point  of  intersection  of  the 
posterior  axillary  line  with  the  "  projection-line  "  of  the  main 
incisure  just  mentioned  ;  it  passes  forward  horizontally  to  the 
sternum,  ending  at  the  upper  part  of  the  sternal  end  of  the 
fourth  intercostal  space.  Above  this  line  is  the  upper  lobe 
of  the  right  lung,  between  the  fourth  and  sixth  ribs  is  the 
middle  lobe,  and  below  the  sixth  rib  is  the  lower  lobe. 

THE   URINARY   ORGANS. 

Where  are  the  kidneys  situated? 

Deeply  in  the  loins,  one  on  each  side  of  the  vertebral  col- 
umn, each  kidney  reaching  from  the  upper  border  of  the  twelfth 
thoracic  to  the  third  lumbar  vertebra,  the  right  a  little  lower  than 
the  left ;  they  lie  embedded  in  a  mass  of  fat  behind  the  perito- 
neum, and  enter  four  regions — the  hypochondriac  and  epigastric 
above,  the  lumbar  and  umbilical  below. 

What  are  their  size  and  weight  ? 

Each  measures  about  four  inches  in  length,  two  and  one- 
half  in  breadth,  and  one  and  one-quarter  or  one  and  one-half 
in  thickness;  they  weigh,  in  the  male,  from  four  and  one-half 
to  six  ounces  ;  in  the  female,  four  to  five  and  one-half  ounces. 

Describe  their  relations. 

The  anterior  surface  of  the  right  Mdney  is  in  relation  with 
the  right  lobe  of  the  liver,  descending  duodenum,  ascending 
colon,  and  the  hepatic  flexure. 

T\\Q^  anterior  surface  of  the  left  kidney^  with  the  great  end  of  the 
stomach,  lesser  sac,  tail  of  the  pancreas,  and  descending  colon. 

The  jiosterior  surface  of  each  rests  upon  the  crus  of  the  dia- 
phragm and  the  anterior  layer  of  the  lumbar  fascia  separating 
it  from  the  quadratus  lumborum  and  psoas  magnus. 

The  superior  extremity  is  embraced  by  the  suprarenal  capsule 
and  the  liver  on  the  right  side  ;  by  the  capsule  and  the  spleen 
on  the  left  side. 

The  inferior  extremities  are  two  inches  above  the  iliac  crests. 


THE  URINARY  ORGANS.  313 

The  right  external  bonier  is  covered  by  the  liver,  the  left  by 
the  spleen. 

A  fissure,  or  hihim,  one  inch  long  at  the  central  portion  of 
the  internal  border,  opens  into  a  cavity,  the  shuts;  through  it 
pass   the  lymphatics^   also   the   renal  vein   in   front,   the   renal 
artery  next,  and   the    ureter,  or    excretory  duct,  behind   and 
below. 

Describe  the  naked-eye  appearances  of  a  longitudinal  sec- 
tion of  a  kidney  (Fig.  126). 

The  kidney  proper  consists  of  a 

Cortical  substance'^,  composed  of  convoluted  and  straight 
uriniferous  tubules,  blood-vessels,  nerves,  lymphatics,  con- 
nective tissue,  and  Malpighian  bodies,  and  is  prolonged  down 
between  the  pyramids,  forming  the  cohmins  of  Berlin  ;  a  fibrous 
capsule  envelops  the  organ,  passes  into  the  sinus  which  it  lines, 
blending  with  the  sheaths  of  vessels,  nerves,  and  the  calices ; 
the 

Medvllary  substance'^  consists  chiefly  of  straight  tubuli 
uriniferi,  "  Henle's  loops,"  and  blood-vessels,  arranged  in  eight 
to  eighteen  piyramids  of  Malpiglii'^' ,  whose  apices  are  embraced 
by  the  calices  of  the  pelvis  of  the  ureter  ;  the 

Pelvis  consists  of  eight  calices,  cup-like  tubes,  embracing 
the  apices  of  eight  to  eighteen  Malpighian  pyramids,  con- 
■  verging  to  form  two  infnidibnla,  these  again  joining  to  form 
the  jfclvis,  which  gradually  contracts  into  the  7ireter  or  ex- 
cretory duct. 

Describe  the  tubuli  uriniferi'^  (Fig.  127). 

They  commence  in  a  dilatation  called  the  cajisule  of  Bow- 
man^, which  encloses  a  vascular  Malpifjhian  fnff,  and  terminate 
by  opening  on  the  free  surfaces  of  the  papillae  '^  Next  follows 
the  neclc,  and  the 

Proximal  convoluted  tubule^,  the  much  convoluted  portion 
after  leaving  the  capsule  of  Bowman  and  situated  in  the  corti- 
cal portion. 

The  spiral  tubule  of  Schachowa\  next  succeeding,  where  the 
tubule  approaches  the  medullary  portion  in  a  spiral  manner  ; 
now  entering  the  medullary  portion,  the  tubule  suddenly  be- 
comes smaller,  (juite  straight,  dipping  down  into  the  pyran)ids, 
as  the  descending  limb  of   llenles  loop;    forming  a   hjop  ^  it 


314 


ESSENTIALS  OF   HUMAN  ANATOMY. 


enlarges,  ascends  spirally,  diminislics  its  caliber,  and  reenters 
the  cortical  substance,  ascending  limb  of  Uenlen  loop'  ^ ;   next 


ret 


Fig.  126— a  longitudinal  section  of  the  kidney  (Leidy). 

it  becomes  angular,  the  irregular  tubule,  then  convoluted,  called 

the 

Distal  convoluted  tubule^^,  '\  which  terminates  in  a  narrow 

Curved  or  Junctional  tubule  '^  and  finally  joins  the 

Straight  collecting  fubule^'\  ^\  terminating  on  the    summit 

of  one  of  the  papillae. 

Describe  these  straight  tubules  ^'\  ^\ 

Traced  into  the  pyramids  from  the  papillae,  they  run  from 


THE  URINARY  ORGANS.  315 

tlie  apex  to  the  base,  dividing  dichotomously,  receiving  the 
curved  tubules,  to  enter  the  cortex  much  increased  in  number, 
where  they  form  conical  masses,  called  the  pyramids,  of  Fer- 
rein,  with  their  bases  toward  the  medullary  portion. 

Describe  the  epithelium  of  the  uriniferous  tubules. 

It  varies  in  different  portions,  being  flattened,  polyhedral, 
angular,  striated,  and  columnar. 

Describe  the  Malpighian  tufts,  or  vascular  glomeruli. 

Each  is  formed  by  a  renal  afferent^  (Fig-  128)  arteriole, 
which,  after  piercing  the  capsule — a  pouch-like  commencement 
of  a  tubulus  uriniferus  lined  with  flattened  epithelium  ^ — 
breaks  up  into  a  tuft  of  vessels  forming  a  plexus,  from  which 
arises  the  efferent  ^  vessel  or  vein.  These  vessels  are  opposite 
the  neck  of  the  tubule,  emerging  from  the  capsule  near  the 
point  of  entrance  of  the  afferent  arteriole.  The  Malpighian 
tuft  or  glomerulus,  surrounded  by  the  capsule  of  Bowman, 
forms  the  two  parts  of  the  Malpigldan  body  or  corpuscle. 

Describe  the  renal  circulation. 

Renal  artery^from  the  aorta,  gives  small  branches  to  the  supra- 
renal capsule,  ureter,  and  surrounding  tissue  ;  two  renal  arteries 
on  one  side  are  frcfjuent ;  it  divides  just  external  to  the  hilum 
into  four  or  five  primary  branches,  which  subdivide  to  form  the 

Arterise  2^rf^J>''i^^  rencdes,  lying  in  the  columns  of  Bertin  ; 
two  of  these  run  along  the  sides  of  each  Malpighian  pyramid, 
giving  off  afferent  branches  to  the  Malpighian  tufts,  and, 
bending  between  the  bases  of  the  pyramids  and  cortex,  send 
off  the  (1)  mferlobular  bi-anches  and  (2)  arteriolse  rectse : 

(1)  Tntcrlobvlar  arteries.,  passing  outward  between  the  pyra- 
mids of  Ferrein  to  the  capsule,  terminating  in  .stellate  plexuses 
beneath  it  (stars  of  Verheyen),  and  also  supplying  afferent 
art<'rioles  to  the  Malpighian  tufts  of  the  cortex,  whence  issue 
effer(;nt  vessels,  forming  a  dense  venons  plexus  around  the 
adjacent  uriniferous  tubules  ; 

(2)  Arteriohi',  rectn .^  or  desee^idine/  brandies.,  passing  from  the 
bases  to  the  apices  of  the  pyramids,  there  to  terminate  in  the 
venous  plexuses. 

The  blood  is  collected  by  the  stellate  venous  2>lcxiises  beneath' 


;i6 


ESSENTIALS  OF  HUMAN   ANATOMY. 


the  capsule,  forming  vensa  infcrlohnlarea^  which  pass  between 
the  pyramids  of  Ferrein,  are  joined  by  branches  emptying  the 
plexuses  around  the  convoluted  tubes  of  the  cortex,  and  join 
the  venae  recta)  at  the  bases  of  the  Malpighian  pyramids  ;  these 
vense  rcctse  being  branches  from  ^>/f.T?<.sr.s  at  the  apices  of  the  med- 
ullary pyramids  formed  by  the  arteriolae  rectae.     The  junction 


'^  PuTioapsiilar  layer 
witluiut  >ial- 
pi^'hian  corpus- 
cles. 


^)  Cortex. 


Inner  stratum  of  cortex,  without 
Malpighian  corpuscles. 


Fig.  127— Uriniferous  tubule  (Leidy). 


of  the  ven^  rccf^  and  vcnse  iiiterlohularrs  forms  the  vcnx  proprise 
renales,  accompanying  the  arteries  of  the  same  name,  which 
receive  venous  twigs  from  the  IMalpighian  tufts  of  the  cortex 
and  unite  in  the  sinus  to  form  the 

Renal,  or  cmnlgevt  vein,  which  passes  out  of  the  hilum  to 
empty  into  the  inferior  vena  cava,  the  right  vein  being  the 
shorter. 


THE   URETERS.  317 

Describe  the  nerves  of  the  kidney. 

They  are  small,  about  fifteen  in   number,  have  ganglia  de- 
veloped upon  them,  and  come  from  the  solar  plexus,  lower  and 


Fig.  128.— a  Malpighian  body  or  corpuscle  (Leidy). 

outer  part  of  the  semilunar  ganglia,  and  from  the  lesser  and 
smallest  splanchnic  nerves,  forming  the  renal  i^lexus^  com- 
municating with  the  spermatic  plexus. 

The  Ureters. 

What  is  the  ureter? 

It  is  the  tubular,  cylindrical,  excretory  duct  of  the  kidney, 
of  the  size  of  a  goose-quill,  fourteen  to  sixteen  inches  long, 
extending  from  the  sinus  of  the  kidney  to  the  base  of  the 
bladder,  into  which  it  opens  by  a  constricted  orifice,  after 
having  passed  obliquely  for  nearly  an  inch  between  its  muscu- 
lar and  mucous  coats  ;  it  has  a  Jihrous  coat  continuous  with  the 
capsule  of  the  kidney  and  fibrous  tissue  of  the  bladder,  a 
mnsryJar  coat  composed  of  two  longitudinal  layers  and  a 
middle  circular  layer,  a  mucous  coat  covered  with  several  layers 
of  many-shaped  epithelial  cells,  "transitional"  epithelium. 

Describe  its  course  and  relations. 

It  passes  obliquely  downward  along  the  posterior  abdominal 


318  ESSENTIALS  OF  HUMAN   ANATOMY. 

wall  beneath  the  peritoneum,  over  the  iliac  arteries,  behind  the 
ileum  on  the  riylit  side,  and  sigmoid  flexure  on  the  le/f,  enters 
the  posterior  false  ligament  of  the  bladder  in  the  male,  with 
the  vas  deferens  between  it  and  the  bladder,  and  enters  the 
bladder  obli({uely  about  one  and  one-half  inches  behind  the 
prostate,  and  two  inches  from  its  fellow  ;  the  internal  openings 
are  20  mm.  apart ;  in  the  female  it  passes  along  the  upper  })art 
of  the  vagina  and  the  side  of  the  cervix  uteri,  being  about 
three-fifths  of  an  inch  distant  from  the  latter ;  the  right  ureter 
lies  close  to  the  outer  side  of  the  inferior  vena  cava. 

The  Bladder. 

What  is  the  bladder? 

The  musculo-membranous  reservoir  for  the  urine,  situated 
between  the  os  pubis  and  rectum  in  the  male,  or  between  the 
OS  pubis,  cervix  uteri,  and  part  of  the  vagina  in  the  female  ; 
moderately  distended  its  dimensions  are  from  above  downward 
and  backward  14  cm.;  breadth,  12  cm.;  antero-posterior  diam- 
eter, 10  cm.;  capacity,  about  one  pint;  in  the  child  it  is  an 
abdominal  organ  and  conical  ;  in  the  adult,  w^hen  empty,  it  may 
be  Y-shaped,  when  distended,  ovoid.  The  bladder  has  a  summit 
and  five  surfaces,  superior,  postero-inferiov  or  hcise,  antero-infe- 
rior  or  pubic,  and  two  lateral  surfaces  or  sides. 

Summit'^^  (Fig.  131)  is  connected  with  the  umbilicus  by  a 
fibro-muscular  cord,  the  uraclius,  and  by  two  fibrous  cords,  one 
placed  on  each  side,  the  obliterated  fetal  hypogastric  arteries; 
the  antero-iu fieri  or  surface  lies  against  the  posterior  surface  of  the 
pubes,  triangular  ligament,  internal  obturator  muscles,  and — 
when  distended — abdominal  walls  ;  the  superior  surfiace,  being 
covered  by  peritoneum,  has  some  coils  of  small  intestine  inter- 
posed between  it  and  the  rectum  and  uterus  in  the  female  ;  the 
obliterated  hypogastric  arteries  cross  its  sides  obliquely  from 
below,  upward  and  forward,  all  below  them  being  uncovered 
with  peritoneum  ;  the  vas  deferens  curves  from  before  back- 
ward along  each  side  to  reach  the  base  of  the  bladder  passing 
across  the  obliterated  hypogastric  vessels  and  along  the  inner 
side  of  the  ureter ;  the 

Fundus  or  base  (Figs.  129  and  131")  is  directed  downward 
and  backward,  resting  in  the  male  upon  the  second  portion  of  the 
rectum,  in  the  female  upon  the  lower  part  of  the  cervix  uteri, 


THE  BLADDER. 


319 


being  adherent  to  the  upper  part  of  the  vagina,  but  separated 
from  the  cervix  by  a  fold  of  peri- 
toneum which  is  reflected  so  as  to 
cover  a  small  portion  of  its  base  ; 
in  the  male  the  peritoneum  passes 
from  the  rectum  to  the  same  portion 
of  the  base. 

The  bladder  has  no  proper  neck 
or  cervix. 


Fig.  129.— Posterior  surface  of 
the  bladder ;  vasa  deferentia 
and  vesiculse  seminales  ( Leidyj. 


How  is  the  bladder  held  in  place  ? 

By  five  true  and  five  false  liga- 
ments;  the  true,  being  made  of 
fascia,  are 

Anterior.^  or  puho-prostatic, 
formed  by  two  folds  of  the  recto- 
vesical fascia  extending  from 
either  side  of  the  pubic  symphysis 
to  the  pubic  surface  of  the  bladder  over  the  upper  surface  of 
the  prostate  gland  ; 

Lateral,  of  the  same  tissue,  passing  between  the  lateral  sur- 
faces of  the  prostate  gland  and  sides  of  the  base  of  the  bladder 
to  the  pelvic  wall ; 

Urachiis'^'^  (Fig.  131),  a  fibro-muscular  cord  covered  with 
peritoneum,  stretching  from  a  point  4  to  20  mm.  anterior  to 
the  apex  of  the  bladder  to  the  umbilicus. 

The  false  ligaments  are  : 

Ty:o  posterior,  folds  of  peritoneum  passing,  in  the  male  from 
the  sides  of  the  rectum,  in  the  female  from  the  sides  of  the 
uterus,  to  the  postero-lateral  aspect  of  the  bladder,  and  con- 
tain the  obliterated  hypogastric  arteries,  the  ureters,  vessels, 
and   nerves. 

Two  lateral,  peritoneal  folds  passing  from  the  iliac  fossa)  to 
the  sides  of  the  bladder. 

Superior '^^  (Fig.  IIU),  a  peritoneal  fold  passing  over  the 
uracil  us,  plica  nrachi,  from  near  the  apex  of  the  bladder  to 
the   umbilicus. 


What  is  the  urachus"  (Fi<?.  131)? 

The  remains  of  a  tubular  canal  connecting  the  bladder  with 
the  allantois  :   it  has  a   stalk  and  may  enclose  a  hollow  space. 


320 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Describe  the  structure  of  the  bladder. 

It  has  four  coats,  viz.  a 

FcritoneaP^^  '^^  (Fig.  131),  covering  the  superior  surface 
from  the  entrance  of  the  ureters  at  the  base  to  its  summit, 
pas.sing  on  to  the  sides,  whence  it  is  reflected  to  the  abdominal 
and  pelvic  walls  :  a 

Muscular,  consisting  of  fibers  spirally  arranged,  forming 
figure-of-eight  loops,  the  more  superficial  being  nearly  longi- 
tudinal, the  deeper  nearly  circular,  and  finally  a  thin  internal 
longitudinal  layer ;  these  form  several  more  or  less  distinctly 
marked  layers,  the  loops  directed  toward,  and  embracing  the 
urachus  and  urethra  respectively,  the  aggregation  of  these 
loops  around  the  beginning  of  the  urethra  forming  the 
sphincter  vesicse ;  the  fibers  passing  in  all  directions  are  con- 
tinued into  the  prostatic  urethra  (Pettigrew)  :  the 

Submucous  coat  is  a  layer  of  areolar  tissue  intimately  blended 
with  mucous  membranes  binding  it  to  the  muscular  coat ;  a 

Mucous  coat,  covered  by  transi- 
tional epithelium,  the  superficial 
layer  of  polyhedral  cells,  below  club- 
shaped  and  smaller  spindle-celled  ;  it 
contains  a  few  mucous  follicles  and 
numerous  racemose  glands  lined  with 
columnar  epithelium  near  the  neck  ; 
it  is  thrown  into  folds  or  rugi£  when 
the  bladder  is  empty. 

What  are  the  muscles  of  the  ure- 
ters? 

Two  oblique  bands  rising  behind 
the  orifices  of  the  ureters  which  con- 
verge, to  be  inserted  bv  a  fibrous 
process  into  the  middle  lobe  of  the 
prostate  gland. 

What   is  the   trigonum   vesicse  or 
trigone  vesical-  (Fig.   130)? 

A    triangular    smooth    surface    at 
the  base  of   the  bladder,  with  apex 
forward,  of  a  paler  color  than  the  re- 
mainder of  the  mucous  membrane, 
which  is  intimately  adherent  to  the  subjacent  tissue  :  the 


Fig.   130.— The   bladder    and 
urethra  laid  open  (Leidy). 


THE   MALE   URETHRA.  321 

Lateral  boundaries  are  two  slightly  marked  ridges  on  each 
side  passing  backward  and  outward  from  the  apex,  formed  by 
the  urethral  opening,  to  the  orifices  of  the  ureters  ■^,  correspond- 
ing to  the  muscles  of  these  ducts,  the  openings  being  placed 
one  and  one-half  inches  apart  (some  say  20  mm.)  and  one  and 
one-half  inches  behind  the  urethral  opening  ;  a  line  of  mucous 
membrane  connecting  the  two  forms  the  base  of  the  trigone, 
called  the  plica  ureterica. 

What  is  the  uvula  vesicae*  (Fig.  130)? 

A  slight  elevation  of  the  mucous  membrane  projecting  from 
the  lower  anterior  portion  of  the  floor  of  the  bladder  into  the 
orifice  of  the  urethra. 

Mention  the  vessels  connected  with  the  bladder. 

Syperior,  middle,  and  inferior  vesical,  and  small  twigs  from 
the  obturator  and  sciatic  arteries  in  the  male,  with  additional 
branches  from  the  uterine  and.  vaginal  in  the  female  ;  the  veins 
form  intricate  plexus'es  around  the  neck,  sides,  and  base,  empty- 
ing into  the  internal  iliac  vein  ;  the  lymphatics  accompany  the 
ves.sels. 

Give  the  nerve-supply  of  the  bladder. 

It  is  bilateral,  coming  from  the  hypogastric  plexus  of  the 
sympathetic  and  third  and  fourth  sacral  nerves,  sometimes  the 
second  sacral  nerve. 

The  Male  Urethra. 

Describe  this  canal. 

It  extends  from  the  neck  of  the  bladder*  to  the  meatus 
urinarius,  measuring  eight  to  nine  inches  ("20.4  cm.),  present- 
ing a  double  curve  if  the  penis  is  flaccid,  but  a  single  one  with 
the  convexity  downward  during  erection. 

Name  and  describe  each  of  its  divisions. 

They  are  the  prostatic  ^  \  membranous,  and  spongy. 

The  prostatic  portion  \^  (Y'lQ.  130),  that  portion  passing 
from  the  base  to  the  apex  of  the  prostate  gland,  running  nearer 
the  upper  surface,  measuring  one  and  a  (juarter  inches  long,  is 
the  widest  and  most  dihitable  section  of  the  urethra  and  is 
spindle-shaped  ;  upon  the  median  aspect  of  the  floor  is  a  nar- 

21 


322 


ESSENTIALS  OF  HUMAN   ANATOMY. 


row  longitudinal  ridge  eiglit  or  nine  lines  long,  three-quarters 
of  an  inch,  the  vertimontanum  or  caput  gaUinagiids^,  containing 
muscular  and  erectile  tissue  ;  on  either  side  is  a  slight  fossa, 
called  the  prostatic  sinus,  its  floor  presenting  the  openings  of 
the  lateral  prostatic  ducts ;  the  ducts  of  the  middle  lobe  open 
above  the  vermnontanum. 

The  sinus  pocularis,  or  vtn-ns  masculinus  ^,  is  a  depression 
extending  about  a  quarter  of  an  inch  upward  and  backward 
beneath  the  middle  lobe  of  the  prostate  in  the  median  line  at 
the  forepart  of  the  verumontanum,  upon  or  within  whose  mar- 
gins are  the  slit-like  orifices  of  the  seminal  or  ejaculatory  ducts^. 

The  membranous  ])ortion^  is  th^t  portion,  three-quarters  of 
an  inch  long,  extending  between  the  apex  of  the  prostate  and 
bulb  of  the  corpus  spongiosum,  which  is  included  between  the 
layers  of  the  triangular  ligament  about  one  inch  beneath  the 
pubic  arch  ;  it  is  surrounded  by  the  compressor  urethral  mus- 
cle, and  is  the  narrowest  portion  of  the  urethra,  except  the 
meatus. 

The  spongy  portion'^,  ^,  the  longest,  measuring  about  six 
inches,  is  so  called  from  being  contained  in  the  corpus  spongio- 
sum ;  it  extends  from  the  membranous  portion  to  the  meatus 
urinarius,  and  presents  a  posterior  dilatation,  that  of  the  bulb  ^ 
(Fig.  131),  and  one  anterior,  the  fossa  navicularis^^  (Fig.  131), 


Fig.  131.— a  vertical  section  of  the  bladder,  penis,  and  urethra  (Leidy). 


the  former  having  opening  into  it  the  ducts  of  Cowper's  glands, 
the  latter  fossa  being  situated  within  the  glans  penis,  having  an 


THE  FEMALE  URETHRA.  323 

opening  directed  forward  in  its  roof,  hiciuia  magna,  the  orifice 
of  a  large  mucous  crypt ;  there  are  also  here  numerous  other 
scattered  openings  of  glands  and  follicles  similarly  directed, 
glands  of  Littre. 

What  is  the  meatus  urinarius  ? 

The  anterior  orifice  of  the  urethra,  a  vertical  slit  about  three 
lines  long,  bounded  on  each  side  by  a  small  labium  ;  it  is  the 
narrowest  portion  of  the  canal. 

Describe  the  structure  of  the  urethra. 

It  possesses  four  coats,  viz.  a  mucous,  forming  a  part  of  the 
genito-urinary  membrane  internally  and  continuous  with  the 
skin  externally,  having  numerous  mucous  glands  imbedded  in 
its  submucous  tissue,  which  open  on  its  free  surface ;  it  is 
covered  with  columnar  epithelium  except  near  the  meatus, 
where  it  is  squamous. 

The  suhmucons  coat  is  a  thin  layer  of  vascular  erectile  tissue, 
surrounding  especially  the  prostatic  and  membranous  portions. 

External  to  this  is  the  muscular  coat  (muscularis  mucosae)  ; 
in  the  prostatic  portion  it  consists  of  an  inner  longitudinal  and 
an  outer  circular  layer  of  unstriatcd  muscle-fibers  ;  they  are 
directly  continuous  with  the  muscle-layers  of  the  bladder. 
Both  layers  are  present  in  the  membranous  portion  and  aid 
the  sphincteric  action  of  the  striated  urethral  muscles.  Both 
layers  gradually  cease  in  the  spongy  portion,  the  circular  layer 
disappearing  first;  a  few  oblique  and  longitudinal  fibers  remain 
in  the  anterior  part  of  this  portion. 

A  variable  y?^>Y>»s  tunic  surrounds  the  muscular  layer,  giving 
support  and  strength  to  the  canal. 

The  Female  Urethra. 

Describe  this  canal. 

It  is  about  one  and  one-half  inches  long,  extends  from  the 
]>ladder  to  the  meatus  urinarius  above  the  anterior  vaginal  wall, 
pierces  the  triangular  ligament,  and  is  embraced  by  the  com- 
pressor nrcthnii  muscle  as  in  the  male  ;  its  structure  is  similar  to 
that  of  the  rmile  urethra;  it  is  lined  with  laminated  squamous 
epithelium  merging  into  spheroidal  near  the  bladder;  it  is  a 
quarter  of  an  inch  in  diameter,  but  is  capable  of  much  greater 


324  ESSENTIALS  OF  HUMAN   ANATOMY. 

dilatation ;  the  anterior  opening  (meatus)  is  situated  near 
the  anterior  margin  of  the  vagina,  about  one  inch  behind  the 
clitoris,  surrounded  by  a  prominence  of  mucous  membrane. 

THE   MALE   GENERATIVE   ORGANS. 

Where  is  the  prostate  gland  situated  (Fig.  130)? 

It  surrounds  the  neck  of  the  bladder  and  commencement  of 
the  urethra,  lying  in  the  pelvic  cavity  posterior  to  the  deep 
perineal  fascia,  behind  and  below  the  symphysis  pubis  upon  the 
rectum  ;  through  it  pass  the  urethra  and  ejaculatory  ducts. 

Describe  its  form  and  size. 

It  resembles  a  horse-chestnut  in  form,  measures  one  and  a 
half  inches  transversely,  one  inch  antero-posteriorly,  three- 
quarters  of  an  inch  in  depth,  and  weighs  four  and  a  half  to 
four  and  three-quarters  drachms  ;  the  base  is  directed  backward 
toward  the  bladder  ;  it  consists  of  two  equal-sized  lateral  lobes 
and  a  middle  lobe,  which  is  a  small  band  or  rounded  triangular 
eminence  placed  between  the  lateral  lobes  immediately  in  front 
of  the  base  of  the  bladder  and  below  the  commencement  of  the 
urethra. 

Describe  its  structure. 

It  is  composed  of  numerous  follicular  pouched  glands  open- 
ing into  elongated  canals  which  join  to  form  twelve  to  twenty 
excretory  ducts  imbedded  in  the  interstices  of  a  stroma  formed 
of  interlacing  bundles  of  unstriped  muscle,  the  whole  being 
inclosed  in  a  fibrous  capsule.  Muscular  tissue  predominates 
over  the  glandular. 

What  retains  the  gland  in  place  ? 

The  pubo-prostatic  ligaments,  posterior  layer  of  the  deep  peri- 
neal fascia,  and  anterior  portions  of  the  levator  ani  muscles. 

Describe  the  situation  and  structure  of  Cowper's  glands. 

They  are  two  small  lobulated  glands  of  the  size  of  peas, 
lying  between  the  two  layers  of  the  deep  perineal  fascia  in 
front,  close  behind  the  bulb  of  the  urethra,  surrounded  by  the 
compressor  urethrae  muscle,  and  opening  by  ducts  one  inch 
long  which  pass  obliquely  forward  beneath  the  mucous  mem- 
brane, on  the  floor  of  the  bulbous  portion  of  the  urethra. 


THE  PENIS.  325 

The  Penis. 

Describe  the  penis. 

It  has  a  root,  body  ^  (Fig.  131),  and  extremity  or  glans 
penis ^,  and  consists  of  three  elongated  cylindrical  masses  of 
erectile  tissue,  composed  of  a  fibrous  sheath  which  sends 
inward  numerous  interlacing  bands  (trabeculae),  forming  nu- 
merous meshes  in  which  lie  the  blood-vessels.  The  upper  two 
cylindrical  bodies  lying  side  by  side,  like  a  double-barrelled 
gun,  are  called  the  corpora  cavernosa  ^ ;  the  third,  much  smaller, 
lying  in  the  median  line  beneath,  like  the  ramrod  of  a  gun,  is 
the  corpus  spongiosum.'^ 

Describe  the  corpora  cavernosa. 

Situated  as  just  described,  they  are  intimately  connected  in 
their  anterior  three-fourths,  where  they  are  in  contact,  present- 
ing a  median  dorsal  groove  for  vessels  and  nerves,  and  an  inferior 
median  groove  for  the  corpus  spongiosum,  while  their  posterior 
fourths  diverge,  forming  the  crura  *,  which  are  attached  to  the 
rami  of  the  pubes  and  to  the  ischia  anterior  to  the  tuber- 
osities ;  near  their  point  of  junction  with  one  another  they 
become  slightly  enlarged,  forming  on  either  side  the  bulb  of 
the  corjnis  cavernosum. 

What  other  structure  secures  the  root  of  the  penis  ? 

The  sxspensior}/  ligament,  a  band  of  fibro-elastic  tissue,  con- 
nected with  the  symphysis  pubis  and  superficial  fascia,  which 
runs  to  the  dorsum  of  the  penis. 

What  is  the  septum  pectiniforme  ^  ? 

It  is  the  anterior  portion  of  the  vertical  septum  between  the 
corpora  cavernosa  which  is  incomplete,  the  fibrous  bands  re- 
sembling the  teeth  of  a  comb  ;  the  septum  and  fibrous  sheath 
contain  numerous  elastic  and  muscular  fibers  in  addition  to  the 
white  fibrous  tissue. 

Describe  the  corpus  spongiosum. 

It  incloses  the  urethra  '^  lying  mcdianly  below  at  the  junc- 
tion of  the  corpctra  cavernosa,  commencing  beliind  in  front  of 
the  deep  perineal  fascia  between  the  crura  of  the  corpora  caver- 
nosa as  a  rounded  enlargement,  the  bulb  **,  which  is  surrounded 


326  ESSENTIALS  OF  HUMAN  ANATOMY. 

by  tlie  accelerator  urini©  muscle.  Anteriorly  it  forms  a  coni- 
cal enlargement,  flattening  from  above  downward,  which  caps 
the  blunted  end  formed  by  the  corpora  cavernosa,  the  glans 
jyenis^,  the  margin  of  whose  base  is  called  the  corona  glandis^ 
and  the  constriction  behind,  the  cervix. 

What  other  parts  of  importance  does  the  penis  present  ? 

The  medtaa  nrinarias,  the  external  orifice  of  the  urethra,  is  a 
vertical  opening  at  the  summit  of  the  glans  penis. 

The  prepuce.,  a  portion  of  the  skin  of  the  penis  prolonged 
forward  so  as  either  completely  or  partially  to  cover  the  glans 
penis,  lined  with  modified  skin  which  covers  the  glans  and 
joins  the  mucous  membrane  at  the  meatus. 

Frenum  preputii^  a  median  fold  of  integument  passing  from 
behind  the  meatus  at  the  bottom  of  a  depressed  raphe  to 
become  continuous  with  the  under  margin  of  the  penis. 

Glaiidnlse  TysonU  odoriferse,,  numerous  small  lenticular  se- 
baceous glands  upon  the  corona  and  cervix  of  the  glans, 
secreting  sebaceous  matter  with  a  peculiar  odor. 

What  is  meant  by  erectile  tissue  ? 

An  intricate  venous  plexus  formed  by  the  interspace  between 
the  fibrous  trabeculse,  the  blood  being  delivered  in  the  follow- 
ing ways  :  (1)  by  arteries  terminating  in  ordinary  capillaries — 
this  is  the  arrangement  in  the  corpus  spongiosum  and  glans ; 
(2)  by  fine  convoluted  arterial  twigs  opening  directly  into  the 
venous  network  by  funnel-shaped  extremities. 

What  are  the  helicine  arteries? 

Convoluted,  tendril-like  arterial  branches  opening  directly 
into  the  intertrabecular  spaces,  as  just  explained,  most 
abundant  in  the  back  parts  of  the  spongy  and  cavernous 
bodies. 

Name  the  vessels,  lymphatics,  and  nerves  of  the  penis. 

The  arteries  are  all  branches  of  the  internal  pudic,  viz. 
Artery  of  the  bidh,  on  each  side,  to  the  corpus  spongiosum. 
Arteries  of  the  corpora  caver)iosa,  to  these  bodies. 
Dorsal  arteries  of  the  jjenis,  to  the  corpora  cavernosa,  glans, 
prepuce,  and  skin.     The  veins  return  the  blood  by  the  dorsal 


THE  TESTES  AND  THEIR  COVERINGS.  327 

vein,  prostatic  and  pudic  venous  plexuses ;  also  by  the  pudic 
and  obturator  veins. 

The  superficial  lymphatics  end  in  the  inguinal  glands,  the 
deep  join  the  deep  pelvic  lymphatics. 

The  nerves  are  branches  of  the  internal  pudic  and  hypo- 
gastric plexus   of  the  sympathetic. 

The  Testes  and  their  Coverings. 

What  are  the  testes  or  testicles  (Fig.  132)? 

They  are  the  procreating  glands,  those  which  secrete  the 
spermatozoa,  are  of  ovoid  form  compressed  laterally,  and  are 
each  obliquely  suspended  in  the  scrotum  by  the  spermatic  cord. 
They  measure  in  length  one  and  a  half  inches  (o7  mm.),  one 
inch  in  breadth  (24  mm.),  and  one  and  a  quarter  inches  antero- 
posteriorly  (28  mm.),  weighing  from  six  to  eight  drachms,  the 
left  being  slightly  the  larger. 

What  is  the  scrotum? 

A  cutaneous  pouch  containing  the  testicles  and  part  of  the 
spermatic  cords,  formed  of  integument  externally  and  beneath 
this  of  a  reddish  contractile  layer,  the  dartos,  continuous  with 
the  contiguous  superficial  fascia  and  sending  inward  a  parti- 
tion, the  septum  scroti,  dividing  the  scrotum  into  two  compart- 
ments. 

Describe  the  coats  of  the  testis. 

They  are,  the  tunica  vaginalis,  a  serous  coat  originally  derived 
from  the  peritoneum,  consisting  of  a  portion  investing  the  testis 
and  epididymis,  the  visceral  layer,  or  tunica  vagin((lis  propria, 
and  a  parietal  layer,  or  tunica  vaginalis  reflexa  ;  the 

Tunica  alhuginra  is  formed  of  white  fibrous  tissue  surround- 
ing tlie  gland  and  reflected  into  its  interior  at  its  postero-supe- 
rior  border  to  form  an  incomplete  vertical  partition,  the  meili- 
astinum  testis,  or  corpus  Jfigliniori,  from  which  filtrous  septa 
pass,  frahecuhe,  separating  the  glandular  lo])ul('S  ;   the 

Tunica  vasculosa,  or  pia  mater  testis,  consists  of  a  plexus  of 
blood-vessels  bound  together  by  areolar  tissue,  which  invests 
the  inner  surface  of  the  tunica  albuginea  and  sends  off  proc- 
esses between  the  lobules. 


328  ESSENTIALS  OF  HUMAN   ANATOMY. 

What  is  meant  by  the  coverings  of  the  testis? 

The  structures  with  which  the  testes  become  invested  in 
their  passage,  previous  to  birth,  from  the  abdomen  along  the 
inguinal  canals  into  the  scrotum. 

Name  these  coverings. 

J.      '      [■  scrotum,  closely  adhering  to  each  other. 

Inter  columnar^  or  external  spermatic  fascia,  derived  from  the 
margins  of  the  external  abdominal  ring. 

Cremaster  muscle  and  fascia^  derived  from  the  lower  border 
of  the  internal  oblique  muscle  (some  authors  deny  this). 

Infundihuliform,  or  fascia  2)rojwia,  a  downward  continuation 
of  the  infundibuliform  process  of  the  transversalis  fascia. 

Subperitoneal  areolar  tissue  comes  next,  then  the  tunica  vag- 
inalis, derived  from  the  peritoneum. 

Describe  the  structure  of  the  testis. 

It  consists  of  some  eight  hundred  to  nine  hundred  seminif- 
erous tubules,  one-two-hundredths  to  one-one-hundred  and  fifti- 
eth of  an  inch  in  diameter,  convoluted  so  as  to  form  three  hun- 
dred conical  lobules,  with  apices  toward  the  mediastinum  ;  the 
tubes  then  unite  to  form  twenty  or  thirty  larger  ducts,  one- 
one-fiftieth  of  an  inch  in  diameter,  called  the  vasa  recta",  which, 
passing  upward  and  into  the  mediastinum,  form  a  close  network 
of  anastomosing  tubules,  the  rete  testis;  these  at  the  upper  end 
of  the  mediastinum  terminate  in  twelve  to  twenty  vasa  effer- 
entia\  perforate  the  tunica  albuginea,  and  become  enlarged  and 
convoluted,  forming  coni  vasculosis,  W'hich  aggregated  compose 
the  globus  major  of  the  epididymis ;  the  tubules  consist  of  a 
membrana  propria  lined  with  a  layer  of  polyhedral  cells,  with 
two  or  more  inner  layers  of  spheroidal  cells,  which  divide  into 
epithelial  cells  ultimately  to  become  converted  into  spermatozoa; 
the  vasa  recta  and  tubes  of  the  rete  testis  have  thin  w^alls  lined 
with  one  layer  of  squamous  cells ;  the  vasa  eifercntia  and  epi- 
didymis have  thicker  walls,  containing  muscular  tissue,  and  are 
lined  with  columnar  epithelium. 

What  is  the  epididymis? 

A  convoluted  tube,  some  twenty  feet  long,  lying  along  the 
posterior  border  of  the  testis,  commencing  on  the  testicle  side 


THE  TESTES  AND  THEIR  COVERINGS.  329 

by  a  convergence  of  the  tubes  of  the  coni  vasculosis  and  ending 
in  the  single  vas  deferens  beyond. 

Describe  its  various  parts. 

The  glohiis  major  ^  is  formed  by  the  coni  vasculosi,  or  efferent 
dticfs,  which  open  at  intervals  into  the  single  duct  forming  the 
epididymis  ;  the 

Bodij^  is  the  central  portion,  formed  by  the  convolutions  of 
the  tube  bound  together  by  delicate  areolar  tissue  ;  the 

Globus  minor ^  is  the  lower  enlarged  portion,  composed  as  the 
body  is,  and  connected  to  the  testis  by  fibrous  bands  and  areo- 
lar tissue ;  the 

Vas  aherrans  is  a  narrow  tube,  occasionally  extending  up  into 
the  cord  for  two  or  three  inches,  and  ending  in  a  blind  ex- 
tremity, connected  with  the  lower  part  of  the  tube  of  the  epi- 
didymis, or  commencement  of  the  vas  deferens  ;  the 

Hydatids  of  Morgagni  are  small  bodies  attached  to  the  globus 
major  or  upper  portion  of  the  testicle  by  pedicles ;  they  are 
probably  the  remains  of  the  duct  of  M'dller ;  one  is  very  con- 
stant. 

Describe  the  vas  deferens'^. 

It  is  the  excretory  duct  of  the  testis,  and  is  a  continuation 
of  the  epididymis,  commencing  at  the  globus  minor ^  to  ascend 
along  the  posterior  side  of  the  testis  and  epididymis,  back  of 
the  spermatic  cord,  through  the  inguinal  canal  to  the  internal 
abdominal  ring,  whence,  passing  into  the  pelvis,  it  crosses  the 
external  iliac,  curves  around  the  epigastric  artery  to  reach  the 
side,  then  by  a  curve  downward  and  backward,  the  base  of  the 
bladder  internal  to  the  ureter^  (Fig.  129)  ;  here  it  lies  between 
the  bladder  and  the  rectum,  coursing  along  the  inner  border  of 
the  seminal  vesicle^,  becoming  enlarged  and  sacculated,  the  am- 
pulla, but  narrowing  at  the  base  of  the  prostate,  where,  joined 
by  the  duct  of  the  vesicula  seminalis^,  it  forms  the  ejaculatory 
diict^.  It  is  one  foot  long,  or  two  if  unravelled,  is  about  one 
and  a  quarter  lines  in  diameter,  its  lumen  but  one-third  line 
(0.7  mm.)  ;  it  has  thick,  rigid  walls,  presenting  a  hard,  cord- 
like sensation  when  rubbed  between  the  fingers. 

What  are  the  vessels  of  the  testis  and  its  coverings  ? 

The  gland  itself  is  supplied  by  the  spennatic  artery""  (Fig- 


330 


ESSENTIALS  OF  HUMAN  ANATOMY. 


132),  the  coverings  receive  blood  from  the  siipprftcial  external 

pmlic  and  the  deep  external 
puilic  from  the  femoral,  super- 
ficial perineal  from  the  inter- 
nal pudic,  cremasteric  from  the 
epigastric,  and  artery  of  the  vas 
deferens  from  the  superior 
vesical. 

The  veins  leave  the  back  of 
the  testicle,  forming  the  jiam- 
piniform  p)lexus^  which  ends 
in  a  single  trunk  emptying  on 
the  right  side  into  the  inferior 
vena  cava,  on  the  left  into  the 
left  renal  vein. 

Veins  of  the  same  name  as 
the  arteries  supplying  the  cov- 
erings, return  blood  to  the  fem- 
oral, external,  and  internal 
iliac   veins. 


Fig.  132.— Vertical  section  of  the 
testicle  (Leidy). 


What  nerves  go  to  each  testi- 
cle and  its  coverings  ? 

Branches  from  the  spermatic  plexus  of  the  sympathetic  to 
the  testicle  itself,  to  the  coverings  and  cord  the  ilio-iuguinal, 
ilio-liypogastric^  tiro  superjicial  perineal,  inferior  pudendal,  and 
genital  branch  of  the  genito-crural  nerve. 

What  are  the  component  parts  of  the  spermatic  cord  ? 
Vas  deferens,  Spermatic  nerve-jdexus, 

Spermatic  artery,  Branch  of  the  ilio-inguinal  nerve, 

Cremasteric  artery,  Branch  of  the  genito-crural  nerve, 

Artery  of  the  vas  deferens,    Vas  aherrans  (inconstant), 

Lymphatics, 

Remains  of  the  peritoneal  jwnch. 

These  form  a  cord  bound  together  by  connective  tissue,  in- 
vested by  fascine  brought  down  by  the  testicle,  about  four 
inches  long,  extending  from  the  globus  minor  to  the  internal 
abdominal  ring. 

Describe  the  vesiculse  seminales. 

They   are    two   lobulated   membranous    receptacles  for  the 


Spermatic  veins, 
Areolar  tissue, 


THE  FEMALE  ORGANS  OF  GENERATION.    331 

semen,  which  they  dilute  with  their  own  secretion.  They  are 
pyramidal  in  form,  are  about  two  inches  (50  mm.)  long  by  five 
lines  broad,  by  two  to  three  lines  thick,  and  lie  in  contact 
with  the  base  of  the  bladder,  diverging  from  each  other  from 
the  base  of  the  prostate  to  near  the  entrance  of  the  ureters  ; 
they  join  by  their  anterior  pointed  extremities  with  the  vas 
deferens,  forming  on  each  side  the  ejaculatory  diict'^  (Fig.  129), 
terminating  in  the  prostatic  urethra  by  a  slit-like  orifice  on  each 
side,  just  upon  or  within  the  margin  of  the  sinus  poadaris^ 
(Fig.  130)  at  the  front  of  the  verumontanum. 

Describe  the  descent  of  the  testes. 

During  early  fetal  life  the  testes  lie  at  the  back  part  of  the 
abdomen,  behind  the  peritoneum,  just  below  and  in  front  of 
the  kidneys  ;  attached  to  the  lower  end  of  the  epididymis,  and 
attaining  its  full  development  from  the  fifth  to  the  sixth  fetal 
month,  is  the  gubeniacnlmn  testis,  vi\\\Q\\  contains  muscular  tis- 
sue ;  this  divides  below  into  three  portions,  passing  to  Pou- 
part's  ligament,  to  the  os  pubis  and  rectus  muscle,  and  to  the 
dartos  at  the  bottom  of  the  scrotum  ;  the  gubernaculum  is 
supposed  to  contract  and  so  cause  descent  of  the  testicle,  but 
this  is  a  moot  point.  Between  the  fifth  and  sixth  months  each 
testis  reaches  the  iliac  fossa,  by  the  seventh  it  enters  the  inter- 
nal abdominal  ring,  by  the  eighth  month  it  has  reached  the 
scrotum,  invaginating  from  behind  the  preformed  peritoneal 
sac,  jJ7'oc*:^s.s>/.s  vaginalis,  the  upper  part  of  which  usually 
becomes  obliterated  just  before  birth,  the  lower  portion  then 
forming  the  tunica  vaginalis  testis  completely  cut  off  from  the 
abdominal  cavity  ;  the  other  structures  in  front  of  the  testis 
are  likewise  carried  onward,  forming  its  covering,  as  already 
described. 

THE   FEMALE  ORGANS  OF  GENERATION. 

What  is  the  vulva  (Fig.  VA?,)? 

The  term  includes  the  following  organs  : 

Lahia  7ninora  '^  Vaginal  orifice  ^^, 

Mons  Veneris*,  Clitoris^, 

Lahia  majora  ^,  Meatus  vrinarius  '*. 

These    parts    are    also    called    the  ^mdendmv    and   external 
organs  of  generation. 


332 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Describe  the  mons  Veneris*. 

It  is  a  rounded  eminence  surmounting  tlie  vulva  in  front  of 
the  symphysis  pubis,  formed  by  a  collection  of  fatty  tissue, 
and  at  puberty  becomes  covered  with  hair. 

Describe  the  labia  majora^  and  minora '\ 

The  labia  majora^  2Lxe  two  prominent  longitudinal  cutaneous 
folds  passing  downward  from  the  mons  Veneris  to  the  anterior 
part  of  the  perineum,  enclosing  the  common  urogenital  space. 
Each  labium  is  formed  externally  of  hair-covered  skin,  inter- 
nally of  skin,  enclosing  between  these  hiyas  fatty  areolar  tissue 
and  a  structure  resembling  the  dartos  of  the  scrotum,  to  which 
they  correspond;  the  junction  of  the  labia  in  front  constitutes 
the  anterior  commissure ;  the  posterior  commissure  isafold  of  skin. 

The  labia  minora,  or  nymphse,'^^,  are  two  thin  cutaneous  folds 
containing  numerous  sebaceous  glands,  inside  the  labia  majora, 
running  from  the  clitoris'' — where  they  form  a  hood-like  pre- 
puce and  frenum — obliquely  downward  for  about  one  and  a 
half  inches  on  each  side  of  the  vaginal  orifice,  to  be  lost  in  the 
labia  majora. 

Describe  the  remaining  structures  forming  the  vulva. 

The  clitoris^  is  a  small  penis  with  root,  body,  and  glans, 
composed  of  two  corpora  cavernosa  formed  of  erectile  tissue 

attached  to  the  rami  of  the  pubes  and 
ischium  by  two  crura  ^;  it  has  a  sus- 
pensory ligament  and  two  erectores 
clitoridis  muscles. 

The  vestibuleis  the  triangular  smooth 
surface  below  the  clitoris,  bounded  on 
each  side  by  the  labia  minora. 

The  meatus  iirinarius^*  is  placed  at 
the  back  part  of  the  vestibule,  about 
one  inch  below  the  clitoris,  near  the 
vaginal  margin,  surrounded  by  a 
prominence  of  mucous  membrane. 

The  vaginal  orifice  ^^  is  of  an  ellipti- 
cal form,  usually  more  or  less  closed 
in   the  virgin  by  the   hymen,  and   is 
surrounded  by  the   sphincter   vaginae 
Fig.  133.— The  vulva,  or     muscle,  the   analogue  of  the  male  ac- 
external  generative  organs      ^pi„„„^„_  urinv  mil  sole 


THE  VAGINA.  333 

The  hymen  is  a  thin  fold  of  mucous  membrane,  variously 
shaped,  but  usually  that  of  a  ring  broadest  behind,  or  semi- 
lunar, with  its  concavity  upward,  stretched  across  the  lower 
part  of  the  vaginal  orifice  ;  it  may  occasionally  form  a  com- 
plete occluding  membrane,  the  condition  being  then  known 
as  imperforate  hymen;  it  may  be  practically  absent  in  the 
virgin,  and  again  may  persist  after  copulation,  but  at  that 
time  is  usually  ruptured  ;  after  parturition  it  gives  rise  to 
small,  rounded  elevations  surrounding  the  vaginal  outlet,  called 
carunculse  myrtiformes. 

^  The  glands  of  BarthoUn^^  arc  small,  oblong,  reddish-yellow 
bodies,  lying  on  each  side  of  the  commencement  of  the  vagina, 
each  opening  by  a  long  single  duct  external  to  the  hymen  on 
the  inner  side  of  each  labium  majus ;  they  correspond  to 
Cowper's  glands  in  the  male. 

The  halbi  vestibuU^'^  are  two  oblong  masses — a  venous  plexus 
enclosed  in  a  fibrous  envelope — extending  from  the  clitoris 
along  each  side  of  the  vestibule,  a  Httle  behind  the  labia 
majora. 

The  pars  intermedia  '^  is  another  small  venous  plexus  imme- 
diately in  front  of  the  preceding,  with  which  it  is  continuous  as 
well  as  with  the  glans  clitoridis  ;  these  plexuses  correspond  to 
the  corpus  spongiosum. 

The  fourchette  is  a  small  transverse  cutaneous  fold,  just 
within  the  posterior  commissure  ;  it  is  the  junction  of  the 
labia  minora. 

The  fossa  navicidaris  is  the  space  between  the  fourchette 
and  the  hymen  ;  it  is  generally  artificial,  not  normal. 

The  Vagina. 

Describe  it. 

It  is  a  cylindrical  membranous  canal  flattened  from  before 
backward,  lying  between  the  rectum  and  the  bladder,  extending 
from  the  vulva  to  the  uterus,  curved  backward  and  upward, 
conforming  to  the  axis  of  the  pelvis  and  of  the  outlet.  Narrow 
at  its  orifice,  it  is  larger  above,  its  anterior  wall  measuring 
about  two  and  a  half  inches,  its  posterior  three  and  a  half,  being 
attached  higher  up  on  the  cervix  uteri  behind  than  in  front. 

Describe  its  structure. 

It  is  formed  of  an  external  layer  of  fibrous  tissue,  a  muscu- 


334  ESSENTIALS  OF  HUMAN   ANATOMY. 

lar  coat,  and  a  lining  mucous  membrane  with  a  median  anterior 
and  a  posterior  raphe  or  ajhinins  of  the  cayina^  which  give  oflF 
transverse  rugae  ;  mucous  glands  are  absent ;  the  epithelium 
is  squamous. 

Give  the  relations  of  the  vagina. 

Its  anterior  surface  is  in  relation  with  the  base  of  the  bladder 
and  urethra ;  the  jwsterior  surface  is  in  relation  with  the  rec- 
tum, its  lower  four-fifths  being  separated  from  it  by  the  peri- 
neum and  connective  tissue,  its  upper  fifth  by  a  recto-uterine 
fold  of  peritoneum,  forming  Douglass  cul-cle-sac  ov jjouch. 

Laterally^  above  it  gives  attachment  to  the  broad  ligaments 
of  the  uterus,  below  to  the  levatores  ani  muscles  and  recto- 
vesical fascia. 

The  Uterus  and  its  Appendages. 

Describe  the  position  and  parts  of  the  uterus  (Fig.  134). 

It  is  the  organ  of  gestation,  situated  in  the  pelvic  cavity 
between  the  rectum  and  bladder,  opening  below  into  the  vagina, 
which  is  attached  around  its  cervix.  It  is  pear-shaped,  flat- 
tened from  before  backward,  is  about  three  inches  long,  two 
inches  in  breadth  at  the  upper  part,  and  one  inch  thick,  weigh- 
ing from  one  to  one  and  a  half  ounces  (33  to  41  gm.)  ;  it  pre- 
sents for  examination  the 

Funchis"^^  which  is  convex,  covered  with  peritoneum,  and 
placed  below  the  level  of  the  brim  of  the  pelvis ;  the 

Body  gradually  narrows  from  the  fundus  to  the  neck,  with 
the  anterior  flattened  surface  covered  with  peritoneum  as  far  as 
the  internal  os.  and  a  posterior  peritoneum-covered  convex  sur- 
face, while  each  lateral  margin  is  concave,  afi'ording  attachment 
to  the  Fallopian  ^  tube  above,  to  the  round  ligament  in  front 
and  below  this,  and  to  the  ovarian  ligament  below  and  behind 
both ;  the 

Cervix'^  \'^  the  lower,  rounded,  constricted  portion  of  the 
uterus,  which  lies  partly  above  the  vagina  and  partly  within 
it ;  it  consists  of  three  zones,  upper,  lower,  and  middle  ;  supra- 
vagincd^  intravagincd,  the  middle  zone  affording  attachment  to 
the  vaginal  walls. 

Cavity  of  the  body  is  small,  triangular,  flattened  from  before 
backward,    its  upper    extended   lateral    angles    being   funnel- 


THE   UTERUS  AND  ITS  APPENDAGES. 


335 


shaped,  at  the  apex  of  which  each  opens  by  a  minute  orifice 
into  the  Fallopian  tube  ;  at  the  inferior  angle  is  the  small  open- 
ing into  the  cavity  of  the  cervix  called  the  os  interauni  or  inter- 
nal OS  uteri ;   the 


Fig.  134.— Anterior  view  of  the  internal  generative  organs  (Leidy). 

Cavity  of  the  cervix  is  spindle-shaped,  flattened  antero-pos- 
teriorly,  and  opens  into  the  cavity  of  the  uterus  above  by  the 
internal  os  uteri,  and  below  into  the  vagina  by  the  external  os 
uteri ;  a  median  longitudinal  crest  of  mucous  membrane  on  the 
back  and  front  walls,  from  which  proceed  obliquely  upward 
other  smaller  ones,  forms  the  arbor  vitse  uterina,  hardly  notice- 
able after  the  first  labor  ;  the 

Os  externum  or  external  os  uteri  (also  os  tineas)*  is  a  trans- 
versely ovoidal  opening  from  the  cervix  into  the  vagina,  which 
presents  an  anterior  and  a  posterior  lip,  both  in  contact  with  the 
posterior  vaginal  wall. 


Describe  the  ligaments  of  the  uterus. 

Six  are  peritoneal  folds,  viz. 

Anterior  or  vesico-uterine.  two  crescentic  folds  passing  be- 
tween the  uterine  neck  and  the  back  of  the  bladder ;   the 

Posterior  or  recto-uterine  pass  from  the  uterus  and  vagina  to 
the  sacrum  and  rectum  ;  the  peritoneal  pouch  thus  formed  be- 
tween the  rectum,  the  uterus,  and  the  upper  fifth  of  the  vagina 
being  called   Douglas  s  or  the  recto-uterine  pouch ;  the 

Tu-f)  lateral  or  hroad  lif/aments"^  (^ij?-  134),  stretched  between 
the  sides  of  the  uterus  and  the  lateral  walls  of  the  pelvis,  dividing 
this  cavity  into  two  portions,  each  containing  between  its  folds 
the  Fallopian  tube",  the  round  ligament'',  ovary  and  its  liga- 
ment, parovarium,  and  connective  tissue. 


336  ESSENTIALS  OF  HUMAN   ANATOMY. 

Describe  the  round  ligaments  of  the  uterus  ^ 

They  are  two  muscular  cords,  four  or  five  iiiclies  long,  com- 
mencing at  the  superior  angles  of  the  uterus  to  pass  forward 
and  outward  through  the  internal  abdominal  ring  into  the  in- 
guinal canal,  to  become  lost  in  the  labia  majora  and  in  the  fatty 
tissue  of  the  mons  Veneris  ;  they  consist  of  dense  fibrous  tissue 
and  unstriped  muscle,  enclosed,  in  the  fetal  state,  by  a  process 
of  the  peritoneum  extending  a  short  distance  into  the  inguinal 
canal,  the  so-called  canal  of  Nuck^  usually  obliterated  in  the 
adult,  but  sometimes  pervious  throughout  life ;  this  corre- 
sponds to  the  processus  vaginalis  of  the  male. 

Describe  the  structure  of  the  uterus. 

The  womb  has  three  coats,  viz. 

A  serous,  derived  from  the  peritoneum,  covering  the  fundus 
of  the  organ,  its  posterior  surface,  and  posterior  part  of  the 
cervix  ;  also  the  whole  of  the  anterior  surface  of  the  body  to 
a  point  opposite  the  internal  os. 

A  muscular,  forming  the  bulk  of  the  uterus,  composed  of 
bundles  of  unstriped  muscular  tissue  interspersed  with  areolar 
tissue,  blood-vessels,  lymphatics,  and  nerves.  The  fibers  are 
disposed  in  three  layers,  viz.  external,  in  front  of  and  behind  the 
fundus  ;  middle  la3''ers,  passing  longitudinally,  obliquely,  and 
transversely  ;  and  internal,  arranged  in  two  hollow  cones  whose 
apices  surround  the  orifices  of  the  Fallopian  tubes,  whose  bases 
fuse  in  the  middle  of  the  uterine  body  ;  at  the  internal  os  these 
fibers  are  circular  and  sphincteric. 

A  mucous,  thin,  smooth,  and  closely  adherent  to  the  subjacent 
parts,  covered  with  columnar  ciliated  epithelium,  and  contain- 
ing numerous  tubular  follicles,  most  numerous  in  the  cervix ; 
when  their  ducts  become  obliterated  their  secretion  is  retained, 
forming  small  vesicular  elevations  within  the  os  and  cervix, 
called  ovula  Nahotlii.  The  epithelium  loses  its  cilia  at  the 
lower  third  of  the  cervix. 

Name  the  uterine  vessels  and  nerves. 

The  arteries  are  the  iifen'ue.  from  the  internal  iliac,  and  ova- 
rian.  from  the  aorta,  which  pursue  a  very  tortuous  course  and 
freely  anastomose. 

The  veins  accompany  the  arteries  and  terminate  in  uterine 
plexuses ;    during  pregnancy   they  are   called   uterine  sinuses, 


THE  UTERUS  AND   ITS  APPENDAGES.  337 

consisting  of  the  lining  membrane  of  the  vein  adhering  to  the 
walls  of  canals  channelled  through  the  uterine  substance  ;  the 
Lymphatics  terminate  in  the  pelvic  and  lumbar  glands  ;  the 
Nerves  are  branches  of  the  inferior  hypogastric  and  sper- 
matic plexuses,  and  of  the  third  and  fourth  sacral  nerves. 

What  are  the  Fallopian  tubes? 

They  are  the  oviducts^  two  tubes  four  to  five  inches  long,  ex- 
tending between  the  layers  of  the  broad  ligament  on  each  side 
from  the  superior  angle  of  the  uterus,  passing  out  for  one  inch 
to  the  side  of  the  pelvis,  then  upward,  backward,  and  down- 
ward to  the  inner  surface  of  the  ovary.  Each  has  an  isthmus, 
ampulla,  neck,  and  Jimhriated  extremiti/ ;  the  isthmus  is  the  inner 
constricted  third  of  the  tube,  opening  into  the  uterine  cavity 
by  a  bristle-sized  orifice  ;  the  amp>ulla  is  larger,  tortuous,  curves 
over  the  ovary,  and  includes  one-half  of  the  total  length,  pass- 
ing from  the  isthmus  to  the  neck.  The  ovarian  end  expands 
like  a  trumpet  into  the  Infundlbidum ,  with  its  ostium  ahdomi- 
7iale^^  surrounded  by  fringe-like  Jimhriae,  hence  the  term  fim- 
briated extremity^^;  one  band  is  attached  to  the  ovary,  ovarian 
fimbria,  and  has  a  longitudinal  groove.  Their  walls  are  formed 
of  a  serous  or  peritoneal  coat,  a  muscular,  formed  of  longitudi- 
nal and  circular  fibers,  and  a  mucous  coat  covered  with  ciliated 
columnar  epithelium,  continuous  on  one  side  with  the  uterine 
mucous  membrane,  on  the  other  with  the  peritoneum. 

Describe  the  ovaries". 

They  arc  two  flattened,  ovoid  bodies  suspended  by  their  an- 
terior margins  from  the  back  of  the  broad  ligaments^  in  loops 
of  the  Fallopian  tubes  ;  they  have  mesial  and  lateral  surfaces, 
posterior  and  anterior  borders,  upper  and  lower  extremities 
(His)  ;  they  are  attached  by  their  lower  extremities  to  the 
uterus,  by  the  ovarian  ligaments  and  by  their  upper  ends  to 
one  of  the  fimbria?  of  the  Fallopian  tube  ;  their  dimensions 
are:  leiuffh,  one  and  a  half  inches;  uidth,  three-fourths  of  an 
inch  ;  thickness,  one-half  inch. 

Describe  the  structure  of  the  ovaries. 

Tlicy  consist  of  numerous  (iraafian  follicles  embedded  in  a 
fibrous  stroma,  covered  extermilly  by  modified  peritoneum,  hav- 

22 


338  ESSENTIALS  OF  HUMAN   ANATOMY. 

inf;  columnar  instead  of  squamous  cells  of  a  dull  white  appear- 
ance. 

The  stroma  consists  of  numerous  spindle-cells  with  con- 
nective tissue  and  abundant  blood-vessels  ;  a  condensed  periph- 
eral layer  under  the  epithelium  was  formerly  described  as  the 
tunica  albuglnea.     The  stroma  has  elastic  and  muscular  tissue. 

What  are  the  Graafian  follicles? 

Ovisacs,  minute  vesicles,  70,()()0  at  birth,  diameter  from  y^^ 
inch  (0.25  mm. )  to  the  size  of  a  currant  when  ready  to  rupt- 
ure ;  microscopically  they  are  seen  to  consist  of  an  external 
Jihro-vascular  coat  connected  with  the  stroma  by  a  vascular 
network,  and  an  internal  coat,  or  ot'icajjsule,  lined  with  a  layer  of 
nucleated  cells,  the  membraiia  gramdosa^  which  are  heaped  up 
around  the  ovum  at  that  part  of  the  Graafian  follicle  nearest 
the  ovarian  surfiice.  forming  the  discus  jyroligerus  ;  the  follicle 
contains  also  a  transparent,  albuminous  fluid,  liquor  follicuU, 
supporting  the  ovum. 

Describe  the  human  ovum. 

It  is  a  spherical  mass  of  protoplasm,  yl-g-  inch  (0.2  mm.)  in 
diameter,  just  visible  to  the  naked  eye,  and  consists  of  the 

Vitelline  membrane,  zona  pellncida,  or.  best,  zona  radiata,  as 
it  possesses  strij»  thought  to  be  pores ;  it  surrounds  the 

Vitellus,  or  ?/olk,  a  fluid  containing  granules,  protoplasm,  deu- 
toplasm,  and  a  nucleus  ^-I-q  inch  (0.05  mm.)  in  diameter;  the 
nucleus  is  the 

Germinal  vesicle,  containing  a  smaller  body,  or  nucleolus,  the 

Germinal  spot,  -^-^-^  inch  in  diameter. 

What  is  a  corpus  luteum? 

An  irregular  y tallow  spot  in  the  ovary  at  the  site  of  a  rupt- 
ured Graafian  follicle,  which  diff"ers  in  appearance  according  as 
it  is  a  true  or  false  corpus  luteum. 

Describe  the  differences  between  these  two  kinds. 

The  true  corpus  luteum  is  that  of  pregnancy  ;  it  is  single  and 
increases  up  to  a  certain  point,  at  the  fifth  month  occupying 
sometimes  the  greater  part  of  the  ovary,  and  usually  does  not 
entirely  disappear  until  one  or  two  months  after  delivery. 

The  false  corpus  luteum  is  that  following  ordinary  menstrua- 
tion ;  it  is  much  smaller  and  disappears  in  about  two  months. 


THE  MAMMARY   GLANDS.  339 

Name  the  ovarian  arteries,  veins,  and  nerves. 

The  arteries  are  the  ovarian,  from  the  aorta,  anastomosing 
with  the  uterine  artery  ;  these  vessels  also  supply  the  Fallo- 
pian tubes ;  the 

Veins  follow  the  arteries  and  form  a  plexus  near  the  ovary, 
called  the  pampiniform  plexus. 

The  nerves  are  derived  from  the  inferior  hypogastric  or  pelvic 
plexus,  and  from  the  ovarian  plexus ;  the  Fallopian  tubes  re- 
ceive branches  from  the  uterine  nerves. 

What  is  the  parovarium? 

It  is  also  called  the  organ  of  Rosenmiiller  ;  it  is  the  remains 
of  a  fetal  structure,  and  in  the  adult  consists  of  a  few  closed 
convoluted  tubes  lined  with  epithelium,  one  commonly  ending 
in  a  bulbous  hydatid-like  swelling ;  at  its  tubal  end  the  parova- 
rium is  connected  with  the  remains  of  the  Wolffian  duct — the 
duct  of  Gartner. 

THE   MAMMARY   GLANDS. 

Describe  the  mammae. 

They  exist  in  both  sexes,  being  in  the  male  only  rudimen- 
tary, but  in  the  female  are  two  large  hemispherical  eminences 
situated  toward  the  lateral  aspect  of  the  pectoral  region,  reach- 
ing from  the  midaxillary  line  to  the  sternum,  and  from  the  sec- 
ond to  the  sixth  or  seventh  ribs ;  just  below  the  center  at  the 
fourth  rib  projects  a  conical  prominence,  the  nij^j^le,  surrounded 
by  a  light-colored  areola,  in  which  are  numerous  prominent 
sebaceous  glands,  which  enlarge  during  pregnancy  ;  the  color 
of  both  nipple  and  areola  darkens  during  pregnancy,  and  the 
latter  also  extends  its  area. 

Describe  the  structure  of  the  mammary  glands. 

They  are  composed  of  gland-tissue,  of  fibrous  tissue  connect- 
ing the  lobes,  and  fatty  tissue  in  intervals  between  the  lobes  ; 
the  lobes  consist  of  lobules  formed  of  a  number  of  rounded 
vesicles  grouped  about  a  small  lactiferous  tube  into  which  their 
ducts  open,  and  by  their  union  finally  form  fifteen  or  twenty 
excretory  ducts,  or  tnhidi  lactiferi,  which  converge  toward  the 
areola,  dilating  beneath  it  into  the  ampullar  at  the  base  of  the 
nippl(!,  wh(;re  they  contract  into  straight  tu})OS  perforating  the 
summit  of  the  nipple ;  the  lobules  are  surrounded  by  a  dense 


340  ESSENTIALS  OF  HUMAN   ANATOMY. 

capillary  network  during  lactation,  as  is  also  the  nipple,  which 
becomes  erected  when  irritated,  partly  from  fulness  of  blood, 
partly  from  contraction  of  its  muscular  tissue. 

Name  the  vessels  and  nerves  of  the  mammae. 

The  arteries  are  derived  from  the  thoracic  branches  of  the 
axillary,  intercostal,  and  internal  mammary  arteries;  the 

Veins  form  an  anastomotic  circle  around  the  base  of  the  nip- 
ple, called  the  circnlus  venosus,  from  which  large  vessels  radiate 
to  terminate  in  the  axillary  and  internal  mammary  veins  ;  the 

Lymphatics  chiefly  run  along  the  lower  border  of  the  pectoralis 
major  to  the  axillary  glands,  a  few  pass  through  the  intercostal 
spaces  to  the  anterior  mediastinal  glands ;  the 

Nerves  come  from  the  anterior  and  lateral  thoracic  cutaneous. 

THE   ORGANS   OF   SENSE. 
The  Skin  and  its  Appendages. 

Of  what  parts  does  the  skin  consist  ? 

(a)  Stratum  corneiim, 

^      m   .1        .  ^.7  (b)  Stratum,  hicidimi, 

1.  Lpiaermis,  or  cuticle,       ^  <   ci^     ^  7 

^    n  \     o  r  (c)  Stratum  gramdosnm. 

formed  01  \    )  i\   a^     ^  *     nr  1 

I    (d)  Stratum  mucosum^  or  rete  3lat- 

J  J)  iff  Mi. 

2.  Dei-ma,  cutis  vera^  or  ]    (a)  Stratum  papillare, 

corium,   formed    of   j    (b)  Stratum  reticulare. 

3.  Stratum  suhcutaneum. 

Enumerate  the  accessory  structures  contained  in  the  skin. 

The  tactile  corpuscles.,  in  the  papillae  of  sensitive  parts. 

Ducts    of   the    sebaceous^  .       ^r  i,     n  - v     i  r  ^i 

1    -^     ^    7      7  I  passing  through  all  the  layers  ot  the 

and  siceat-g lands ^  h        V 

Hair-follicles^  j 

JVails,  hairs ^  sebaceous  fflands,  sudoriferous  or  sweat-ylands. 

Where   do  sweat-  and   sebaceous  glands  with  the  hair-fol- 
licles lie? 

Chiefly  in  the  subcutaneous  fatty  tissue,  but  sometimes  in 
the  deepest  layers  of  the  corium. 


THE  SKIN   AND  ITS  APPENDAGES.  341 

Describe  the  epidermis. 

It  is  composed  solely  of  epithelial  cells,  tlie  deepest  layer 
being  columnar,  more  rounded  in  the  middle  portions,  and  flat, 
scaly,  and  horny  on  the  free  surface  ;  the  deepest,  softest  layer 
is  accurately  moulded  upon  the  papillary  layer  of  the  derma, 
and  contains  the  skin-pigment ;  it  is  called  the  stratum  muco- 
r,iim. 

Describe  the  derma. 

It  is  a  tough,  flexible,  and  highly  elastic  tissue,  protecting 
subjacent  parts,  and  is  the  chief  organ  of  the  sense  of  touch  ; 
excretion  is  effected  by  its  various  glands,  and  absorption  also 
takes  place  from  its  surface.     The  derma  consists  of  the 

Pdpillarij  layer^  situated  upon  its  free  surface,  presenting 
innumerable,  minute,  vascular,  conical  eminences,  averaging  in 
length  one  one-hundredth  of  an  inch  by  one  two-hundred-and- 
fiftieth  of  an  inch  in  diameter  at  their  bases,  scattered  irregu- 
larly in  slightly  sensitive  parts,  but  arranged  in  parallel  curved 
lines,  forming  ridges,  in  highly  sensitive  regions  ;  each  papilla 
contains  one  or  more  capillary  loops,  and  one  or  more  nerve- 
fibers,  some  terminating  in  oval-shaped  bodies,  the  tactile  cor- 
puscles, where  touch  is  most  highly  developed ;  Pacinian  cor- 
puscles lie  in  the  subcutaneous  tissue. 

Reticular  layer  contains  interlacing  bands  of  white  fibrous 
tissue,  with  some  yellow  elastic  fibers,  unstriped  muscular 
fibers  wherever  hair  exists,  lymphatics,  blood-vessels,  and 
nerve-plexuses. 

What  are  the  nails  ? 

Flattened,  horny  structures  of  modified  epithelium,  covering 
the  dorsal  aspects  of  the  derma  of  the  distal  phalanges  of  the 
fingers  and  toes.  They  are  convex  externally,  and  have  a  root, 
embedded  in  a  groove  of  skin,  whence  comes  the  growth  in 
length  ;  a  matrix,  that  portion  of  the  derma  beneath,  by  which 
the  nail  grows  in  thickness  ;  the  lunula,  the  white  crescentic 
portion  next  to  the  root,  its  color  due  to  diminution  in  size, 
number,  and  vascularity  of  the  papillfc,  which  are  disposed  in 
longitudinal  rows  elsewhere  in  the  matrix. 

What  are  the  hairs? 

They  are  also  modified  epidermis,  found  everywhere  in  the 


342  ESSENTIALS  OF  HUMAN   ANATOMY. 

skin,  except  the  palms  of  the  hands  and  the  soles  of  the  feet, 
but  vary  in  size.  Each  has  a  root  and  hair-bulb  on  a  hair- 
papilla  in  a  hair-follicle. 

The  root,  bulbous  in  form,  springing  from  a  vascular  papilla 
at  the  bottom  of  an  involution  of  the  epidermis  and  corium, 
called  a  hair-follicle,  which  sometimes  extends  into  the  sub- 
cutaneous cellular  tissue  ;  into  the  hair-follicle  open  two  to  five 
sebaceous  glands ;  hairs  are  raised  by  smooth  muscle-fibers. 
Mm.  arrectores  pilar  urn. 

The  shaft  consists  of  a  central  pith  or  medulla,  a  Jibrons  por- 
tion or  cortical  substance,  and  a  cuticle  of  thin  flattened  scales ; 
the  medulla  is  commonly  absent  in  fine  hairs. 

The  2^(^i"f  is  formed  only  of  the  cuticle  and  cortical  portions. 

Describe  the  sebaceous  glands. 

Most  abundant  in  the  scalp,  face,  armpits,  around  the  anal, 
nasal,  and  oral  apertures,  and  in  the  external  auditory  canal ; 
the  largest  are  the  Meibomian  glands  of  the  eyelids.  They  are 
small  sacculated  glands,  lodged  in  the  stratum  papillare  of  the 
corium  of  nearly  every  part,  except  the  palmar  and  plantar 
surfaces ;  the  ducts  usually  open  into  the  hair-follicles,  but 
sometimes  on  the  general  surface  of  the  skin. 

Describe  the  sweat-glands  (coil  glands). 

Each  has  a  single  excretory  duct  and  coil,  situated  either  in 
the  deepest  portion  of  the  corium,  or  more  usually  in  the  sub- 
cutaneous cellular  tissue,  and  opening  on  the  free  surface  by  a 
spiral  duct  between  the  papilhT3 ;  the  tubes  are  formed  of  an 
external  fibro-cellular  coat,  continuous  with  the  superficial 
layer  of  the  corium,  and  a  lining  of  epithelial  cells  continuous 
with  the  epidermis.  They  are  found  mostly  in  the  palms  and 
soles. 

What  are  their  estimated  number  and  area  ? 

Nearly  two  and  a  half  millions,  forming  an  evaporating  area 
of  about  eight  square  inches. 

The  Organs  of  Taste. 

Where  does  the  sense  of  taste  reside? 

In  the  mucous  membrane  of  the  dorsum  and  sides  of  the 
tongue,  upper  portion  of  the  pharynx,  soft  palate,  and  fauces. 


THE  ORGANS  OF  SMELL.  343 

Are  there  any  special  taste-organs? 

Certain  taste-buds,  flask-like  bodies,  are  supposed  to  com- 
municate with  special  nerves  of  taste ;  no  such  continuity 
has  been  positively  demonstrated.  The  taste-buds  con- 
sist of  spindle-shaped,  flattened  sustentacnlar  cells  externally  ; 
the  central  gustatory  cells  have  a  bulging  body  and  two 
processes,  the  inner  may  be  continuous  with  a  nerve-fibril,  the 
outer  passes  to  a  gustatory  pore  on  the  mucous  surface  and  ends 
in  a  cilium,  taste-hair ;  these  bodies  are  found  in  the  circum- 
vallate  and  fungiform  papilloe,  at  the  sides  of  the  base  of  the 
tongue,  anterior  surface  of  the  soft  palate,  posterior  surface  of 
the  epiglottis,  anterior  surface  of  the  anterior  pillar  of  the 
fauces.  Special  nerves  of  taste  are  probably  the  glossopharyngeal 
by  (1)  lingual  branches  from  the  posterior  third  and  by  (2) 
the  chorda  tympani,  which  communicates  with  this  pair  from 
the  anterior  two-thirds. 

The  Organs  of  Smell. 

Where  does  the  sense  of  smell  reside  ? 

In  the   mucous  membrane  lining  the  upper  portion  of  the 
nasal  fossae,  where  the  olfactory  nerve-filament s  are  distributed. 

Describe  the  nasal  mucous  membrane. 

It  is  also  called  the  Schneiderian  or  pituitary  membrane, 
and  is  continuous  with  that  of  the  pharynx,  Eustachian  tube, 
tympanum,  and  mastoid  cells,  and  with  that  of  the  accessory 
nasal  cavities,  the  frontal,  ethmoidal,  and  sphenoidal  sinuses 
and  antrum  ;  also  through  the  lachrymo-nasal  duct  with  the 
conjunctiva.  Its  epithelium  is  squamous  below  in  the  vestibule, 
in  the  respiratory  region  ciliated  and  columnar,  in  the  olfactory 
columnar  ;  it  contains  numerous  mucous  glands  ;  above,  certain 
nucleated  bodies  arc  found,  the  olfactory  cells  of  Schvltze,  with 
two  processes,  one  running  between  the  epithelial  cells  to  the 
free  surface,  the  other  inward,  to  connect  with  a  terminal  nerve- 
fiber. 
What  vessels  supply  the  exterior  of  the  nose  ? 

La/rr(dis  nasi,  from  tlu;  lacial  to  the  ahc  of  the  nose;  the 
Artery  of  the  septum.,  from  tin;  superior  coronary  ;  the 
Nasal  br<rnr.hes  of  the  ophthalmic  and   infraorbital    to    the 
dorsum   and   sides  of  the  nose  ;  the 

Veins  terminate  in  the  facial  and  ophthalmic. 


344 


ESSENTIALS  OF   HUMAN   ANATOMY, 


What  are  the  vessels  of  the  nasal  fossae? 

Anterior  and  jxjstcn'or  cflunoidiU  IVoiii  the  ophthalmic  to  the 
ethmoidal  cells,  frontal  sinuses,  and  roof;  the 

Spheno-palatiue  and  a  twig  of  the  mnall  ineidngeal  from  the 


Fig.  135.— The  sphenopalatine  ganglion  and  its  branches ;  the  nerve-supply 
of  the  left  nasal  fossa  (Leidy). 

internal  maxillary  to  the  membrane   over  the  spongy  bones, 

meatuses,  and  septum  ;   the 

Alveolar  from  the  internal  maxillary  to  the  antrum  ;  the 
Veins  usually  accompany  the    arteries,   terminating  in   the 

facial  and  ophthalmic  veins,  and  in  the  cranial   sinuses. 

What  nerves  supply  the  exterior  of  the  nose  ? 

Branches  of  the  facial^  infraorhital,  infratrochlear^  and  nasal 
branch  of  the  ophthalmic. 

Describe  the  nerve-supply  of  the  nasal  fossae  (Fig.  135). 

The  olfactory^  is  distributed  to  the  mucous  membrane  over 
the  upper  third  of  the  septum  and  superior  spongy  bones ;  the 

Nasal  branch  of  the  ophthalmic'^  supplies  the  upper  anterior 
part  of  the  septum  and  outer  wall ;  then  it  emerges  to  the  skin 
of  the  ala. 

Anterior  dental  branch  of  the  superior  maxillary  supplies  the 
inferior  turbinated  bone  and  inferior  meatus  :  the 


THE  EYE.  345 

Spheiw-palntine  gmiglion^,  by  the  nam-jialatine  branch '',  sup- 
plies the  middle  of  the  septum  ;  by  the  anterior  j^a^ufine,  the 
middle  and  inferior  spongy  bones. 

The  Vklhui^^  supplies  the  upper  back  part  of  the  septum  and 
superior  spongy  bones,  parts  to  which  are  also  distributed  the 
upper  anterior  nasal  branches  of  the  spheno-palatine  ganglion  ^ 

(For  the  bones  forming  the  nasal  fossae,  see  p.  66.) 

The  Eye. 

Describe  the  eyeball. 

It  is  a  spherical  organ,  with  the  segment  of  a  smaller  trans- 
parent sphere,  the  cornea,  forming  its  anterior  portion,  lying  in 
the  orbit  in  a  cushion  of  fat,  and  held  in  position  by  the  ocu- 
lar muscles,  the  optic  nerve,  conjunctiva,  and  eyelids.  The 
following  points  should  be  studied : 

The  eyeball  is  flattened  from  before  backward,  so  its  trans- 
verse diameter  is  the  longest  of  the  three  ;  it  measures  almost 
one  inch  (y^-^;  24.5  ram.)  ;  a:ntero-j)osterior  diameter^  -f^^  inch 
(24.0  mm.)  ;  vertical  diameter^  -f^  inch  (23.5  mm.). 

Anterior  and  posterior  jwles,  the  centers  respectively  of  the 
cornea  and  the  fundus  oculi. 

Axes  o/ei/ehalls,  or  ocular  axes  which  pass  through  the  poles 
of  each  eye  and  are  nearly  parallel,  not  corresponding  to  the 
axes  of  tlic  orhits,  which  diverge. 

Visual  axis  passes  from  the  yellow  spot  through  the  center 
of  the  curvature  of  the  refracting  media,  so  that  these  axes 
Q.onverge. 

Nodal  pointy  the  center  of  the  curvature  of  the  refracting 
media. 

Equatorud  plane,  that  passing  through  the  center  of  the 
eyeball  at  right  angles  to  the  axis,  dividing  the  globe  into  two 
segments,  an  anterior  and  a  posterior  hemisphere. 

E(pmtor^  the  line  where  the  above-mentioned  plane  cuts  the 
surface  of  the  eyeball. 

Meridional  jdanes,  planes  coinciding  with  the  ocular  axis. 

Meridians,  the  lines  where  the  meridional  planes  cut  the  sur- 
face of  the  eyeball. 

What  is  the  capsule  of  Tenon? 

Tlie  tunica  vaginalis  ocvli,  and  consists  of  a  thin  membranous 
sac  isolating  the  eyeball  jhhI  allowing  free  movement,  arising 
from  the  optic  foramen  behind  to  become  lost  upon  the  scler- 


346 


ESSENTIALS  OF  HUMAN   ANATOMY. 


otic  and  conjunctiva  in  front,  having  a  visceral  layer  for  tWO- 
thirds  of  the  globe,  a  parietal  layer  lining  the  fatty  cushion  in 
which  the  eye  rests,  both  layers  being  lined  by  flattened  endo- 
thelial cells :  the  two  layers  enclose  a  lymph-space,  sjyace  of 
Tenon,  into  which  open  the  lymphatics  of  the  sclerotic,  lymph- 
space  of  the  sheath  of  the  optic  nerve,  and  the  perichoroidal 
space.  The  straight  and  oblique  ocular  muscles  pierce  it  and 
receive  sheaths  from  it ;  it  is  strengthened  by  elastic  and  fibrous 
bands.  Below  and  in  front  of  the  inferior  rectus  a  strengthen- 
ing band  of  fibrous  tissue  runs  from  the  lacrimal  to  the  malar 
bone  like  a  sling,  ligamentum  suspenson'um  oculi. 

What  are  the  tunics  or  coats  of  the  eye  (Fig.  136)? 

The  sclerotic  and  cornea^  the  most  external,  protective  tunic. 


sCLrROTir 

CHOaotO 
RETINA 

HYALOrO    KEMERANC 


CILIA  rv  mitrssts 

CIRCULAR    SINUS 
CAMAL   or    PETIT 


Fig.  136.— Section  of  the  eyeball. 

The  choroid,  iris,  and  ciliary  processes,  the  middle  or  vascular 
tunic. 

The  retina,  the  innermost,  nervous  tunic. 

What  are  the  humors  of  the  eye  ? 

The  refracting  media  are  three  in  number,  viz. 

The  aqueous,  filling  the  anterior  chamber ; 

The  crystalline,  or  crystalline  lens  and  capsule; 

The  vitreous,  filling  the  posterior  four-fifths  of  the  globe. 


THE   EYE.  347 

Describe  the  sclerotic. 

It  is  a  firm,  unyielding  fibrous  membrane,  maintaining  the 
form  of  the  posterior  five-sixths  of  the  globe,  thicker  behind 
than  in  front,  with  a  smooth  white  external  surface  except  where 
tendons  are  attached,  covered  in  front  by  the  conjunctival 
membrane,  and  having  an  inner  rough  brown-stained  surface, 
lamina  fnsca.  Posteriorly  and  to  the  nasal  side  it  is  pierced  by 
the  optic  nerve  with  whose  sheath  it  is  continuous,  the  sclerotic 
at  this  point  forming  a  thin 

Lamina  cribrosa^  through  whose  openings  the  nerve-filaments 
pass,  the  most  central  orifice,  called  the  poms  opticus,  transmit- 
ting the  arteria  centralis  retinaj.  Surrounding  the  cribriform 
lamella  are  numerous  small  openings  for  the  ciliary  vessels  and 
nerves ;  four  venae  vorticosae  emerge  from  it,  and  the  anterior 
ciliary  vessels  pierce  it  near  the  corneal  border.  The  sclerotic 
is  formed  of  white  fibrous  tissue,  mingled  with  fine  elastic  fibers 
and  fusiform  nucleated  cells.     The  following  should  be  noted  : 

Thickness,  2V  inch  posteriorly  (1.  mm.),  ^L-  inch  anteriorly 
(0.4  mm.),  about  6  mm.  from  the  cornea. 

Lamina  fasca,  the  pigmented  tissue  connecting  the  sclerotic 
with  the  choroid  by  fine  threads  which  traverse  a  lymph-space. 

Siihconjuncfival  tissue,  loose  areolar  tissue  binding  the  con- 
junctiva to  the  sclerotic  ;  the 

Arteries  are  few,  coming  from  the  ciliary,  and  forming  a 
coarse  network  ;  the 

Anterior  vascular  zone,  surrounding  the  cornea,  is  formed  by 
the  subconjunctival  branches  of  the  anterior  ciliary  vessels; 
the  existence   of 

Nerves  is  very  doubtful. 

Describe  the  cornea. 

It  is  the  transparent,  projecting,  anterior  sixth  of  the  exter- 
nal tunic.  Tt  is  not  quite  circular,  being  a  little  broader  iti  the 
transverse  than  in  the  vertical  diameter,  and  is  set  in  the  sclerotic 
somewhat  like  a  watch-crystal  in  its  case ;  its  thickness,  one- 
thirty-second  of  an  inch  to  one-twenty-second  of  an  inch,  is 
nearly  the  same  throughout  except  toward  the  outer  margin, 
where  it  is  thinner ;  it  is  non-vascul<ir,  the  capillary  vessels  end- 
ing in  loo[)S  at  its  circumference  ;  the  nerves  are  numerous,  from 
twenty-four  to  forty-five,  and  an;  d(;riv(Ml  from  the  ciliary  and 
form  the  subepithelial  and  intraepitJielial plexuses. 


348  ESSENTIALS  OF  HUMAN   ANATOMY. 

Describe  the  structure  of  the  cornea. 

It  consists,  from  without  inward,  of  the  following  five  layers  : 

Layer  of  anterior  epitheliimi,  deepest  cells  columnar,  next 
polyhedral,  most  superficial  several  layers  of  scaly  cells;  the 

Anterior  limiting  memhrane,  membrane  of  Boioman^  2tVo 
inch  (0.01  mm.)  to  jyVo  ^'^^^  (0.02  mm.)  thick,  forming  a  thin, 
firm,  elastic  layer  consisting  of  extremely  closely  interwoven 
fibrils  similar  to  those  of  corneal  tissue  proper,  but  with  no  cor- 
neal corpuscles ;  it  differs  wholly  from  the  posterior  elastic  lamina. 

The  suhstance  j^roper  is  fibrous,  tough,  unyielding,  contin- 
uous with  the  sclerotic  and  composed  of  sixty  superimposed, 
flattened  lamella3  made  up  of  fibrillar  connective  tissue  con- 
tinuous with  fibers  of  tl>e  sclerotic  ;  the  layers  are  held  together 
by  a  cement-substance  in  which  are  corneal  spaces^  stellate  in 
form,  communicating  with  adjacent  spaces  by  processes,  each 
space  containing  a  similarly  shaped  but  smaller  corneal  cor- 
puscle which  does  not  entirely  fill  it ;  the 

Posterior  elastic  lamina  (ineinhrane  of  Descemet  or  Demours) 
is  a  structureless,  elastic,  brittle,  extremely  thin  membrane,  not 
rendered  opaque  by  water,  alcohol,  or  acids;  its  chief  pecu- 
liarity is  the  tendency  to  roll  upon  itself  with  the  attached 
surface  innermost,  when  separated  from  the  cornea  proper ;  at 
its  circumference  it  breaks  up  into  bundles  of  fibers  forming 
the  liyamcntnm  pectinatum  Jridis,  and  leaving  little  intervals 
or  spaces  between  the  bundles  ;  the 

Posterior  endothelial  layer  is  a  single  layer  of  polygonal, 
transparent,  nucleated  cells,  like  those  lining  other  serous 
cavities. 

Describe  the  choroid  (Fig.  137). 

It  is  a  thin,  dark-brown,  vascular  membrane  investing  the 
posterior  five-sixths  of  the  globe,  terminating  in  front  at  the 
ciliary  muscle,  there  bending  inward  to  form  the  ciliary  proc- 
esses ;  externally  it  is  loosely  connected  by  a  non-vascular 
elastic  layer,  the  lamina  snpraclioroidea,  with  the  lamina  fusca 
of  the  sclerotic ;  each  has  an  endothelial  coat,  thus  forming  a 
lymph-space. 

Choroid  proper  consists  of  two  layers;  the  external  layer  is 
formed  of  the  larger  branches  of  the  ciliary  arteries  and  the 
venae  vorticosae^  interspersed  with  stellate  pigment-cells,  by 
the  union  of  whose  processes  a  delicate  network  is  formed. 


THE   EYE.  349 

Internal  layer,  tunica  Rut/schiana,  or  choriocapillaris,  con- 
sists of  a  fine  capillary  plexus  formed  by  the  short  ciliary  ves- 
sels, which  is  separated  from  the  pigmentary  layers  of  the 
retina  by  the 

Lamina  vitrea,  membrane  of  Bruch,  a  thin,  glassy  layer. 

Between  the  two  layers  of  the  choroid  proper  is  a  thin  bound- 
ary zone  of  fibers,  tapetum  Jibrosum,  producing  a  metallic  luster. 

The  arteriefi  of  the  choroid  are  the  short,  posterior,  ciliary, 
and  the  recurrent  branches  from  the  long  posterior  and  the 
anterior  ciliary. 

The  veins  form  four  or  five  vense  vorficosse  (Fig.  137),  which 
pierce  the  sclerotic  midway  between  the  corneal  margin  and 
the  entrance  of  the  optic  nerve. 

The  nerves  are  the  long  and  short  ciliary  nerves. 

What  are  the  ciliary  processes? 

Sixty  to  eighty  folds  form  a  circle  by  the  plaiting  and  folding 
of  the  choroid  at  its  anterior  margin,  which  are  received  between 
the  corresponding  folds  of  the  suspensory  ligament  of  the  lens; 
they  consist  of  large  and  small  processes,  irregularly  alternat- 
ing ;  the  former  are  about  one-tenth  of  an  inch  long.  They 
contain  ciliary  glands. 

What  is  the  ciliary  body  ? 

It  is  that  portion  of  the  middle  tunic  between  the  choroid 
and  the  iris  formed  of  the  ciliary  muscle  and  ciliary  processes. 

Describe  the  ciliary  muscle^. 

A  grayish  triangular  band  of  unstriped  muscular  fibers  about 
one-eighth  of  an  inch  broad,  thickest  in  front,  thinnest  behind, 
consisting  of  radiating  and  circular  fibers,  the  former  the  more 
numerous,  arising  from  near  the  sclero-corneal  junction  to  pass 
backward  to  the  choroid  opposite  the  ciliary  processes  ;  the 
latter  are  internal,  and  pursue  a  circular  course  around  the  in- 
sertion of  the  iris;  they  are  called  the  circular  ciliary  muscle, 
and  were  formerly  described  as  the  ciliary  ligament. 

Describe  the  circulus  arteriosus  major  and  minor. 

The  former  is  an  anastomotic  ring  formed  by  the  long  ciliary 
arteries  at  the  outer  margin  of  the  iris  ;  the  latter,  a  second 
anastomotic  circle,  is  formed  by  transverse  ofisets  from  ,the  con- 
verging branches  passing  forward  to  the  pupil  from  the  circulus 
major. 


350  ESSENTIALS  OF  HUMAN   ANATOMY. 

Describe  the  iris<=  (Fig.  137). 

It  is  a  thin,  circular,  perforated,  contractile  curtain,  suspended 
behind  the  cornea  in  tlic  aqueous  humor  in  front  of  the  crys- 
talline lens,  forming  the  anterior  portion  of  the  middle  ocular 
tunic.  It  is  formed  of  radiating  and  circular  muscular  fibers, 
and  of  a  fibrous  stroma.  AnteriorJij  it  is  covered  by  a  layer 
of  polyhedral  cells  resting  on  a  fine  hascmcnt-memhrane,  being 
continuous  with  the  membrane  of  Descemet ;  the  posterior 
sur/ice  is  pigmented  epithelium. 

Pujjil,  the  nearly  central  opening  in  the  iris  placed  a  little 
to  the  nasal  side  of  the  center;  diameter  ranges  from  1  mm.  to 
8  mm. 

Ligamentum  pectinatuni  iridis,a,  reticular  tissue,  connecting 


Fig.  137.— The  choroid  and  iris. 

the  iris  with  the  cornea,  derived  from  the  membrane  of  Des- 
cemet, which  sends  fibrous  prolongations  to  the  iris  and  sclero- 
corneal  junction. 

Spaces  of  Fontaiia,  the  intervals  between  the  reticulated 
fibers  of  the  ligamentum  pectinatum  at  the  outer  angle  of  the 
anterior  chamber,  which  communicate  with  a  larger  space  in 
the  sclerotic  close  to  the  sclero-corneal  junction  and  with  the 
anterior  chamber. 

Canal  of  Schlemm,  or  sinus  circularis  iridis,  lined  with  en- 
dothelium, a  venous  sinus,  containing  two  or  three  plexiforra 
veins  receiving  blood  from  the  sclerotic  and  ciliary  plexuses 
and  communicating  with  the  anterior  ciliary  veins. 

Uvea,  a  layer  of  purplish-hued  pigment-cells  on  the  posterior 


THE   EYE.  351 

surface  of  tlie  iris  continuous  with  the  retinal  pigment-layer  of 
the  ciliary  processes. 

Spliincter  pupillst^  the  narrow  hand  of  circular  muscular 
fibers  surrounding  the  pupil  on  its  posterior  surface,  one-fiftieth 
of  an  inch  wide  (0.5  mm.),  supplied  by  the  third  nerve  through 
the  ophthalmic  ganglion 

Dilator  pupillx^  consisting  of  the  radiating  muscular  fibers 
converging  from  the  circumference  of  the  iris  toward  the 
pupillary  margin,  where  they  blend  with  the  circular  fibers  ;  it 
is  supplied  by  sympathetic  fibers  from  the  ophthalmic  gan- 
glion. 

Memhrana  pnpiJlaris^  a  delicate,  transparent,  vascular  mem- 
brane which  occluded  the  pupil  in  the  fetus,  usually  disap- 
pearing about  the  eighth  fetal  month,  but  occasionally  per- 
sisting ;  it  is  nourished  by  many  small  vessels  continued  from 
the  margin  of  the  iris  to  those  on  the  front  part  of  the  lens- 
capsule. 

Arteries  are  branches  of  the  long  and  anterior  ciliary  form- 
ing the  circulus  iridis  major  and  minor  (see  p.  194). 

Veins  empty  into  those  of  the  ciliary  processes  and  into  the 
anterior  and  long  ciliary  veins,  and  communicate  with  the  canal 
of  Schlemm. 

Nerves  are  branches  of  the  ciliary  ganglion,  from  the  nasal 
branch  of  the  ophthalmic  division  of  the  fifth,  the  third  nerve 
going  to  the  sphincter  pupillae  (circular  fibers),  the  sympathetic 
to  the  dilator  pupillae  (radiating  fibers),  and  the  fifth  supplying 
common  sensation. 

What  is  the  retina  ? 

The  innermost  ocular  tunic,  forming  a  delicate,  grayish, 
transparent,  nervous  membrane,  pars  optica  retinae^  ending  near 
the  ciliary  body  by  a  ragged  margin,  the  ora  serrata ;  its 
fibrous  stroma,  covered  by  the  pigment-layer,  passes  forward  to 
the  ciliary  margin  of  the  iris  as  the  pars  ciliaris  retinse ;  behind 
the  iris  is  the  jxns  iridica  retinse. 

Macula  lutea,  or  yellow  spot  of  Sommerhig,  is  an  elliptical, 
elevated  spot  exactly  in  the  center  of  the  retina  posteriorly, 
which  corresponds  ttt  the  axis  of  the  eye  ;  here  vision  is  most 
perfect,  the  retina  being  thin  and  crowded  with  nerve-elements, 
but  destitute  of  rods  and  the  nerve-fiber  layer ;  the  diameter 
is  1  to  2  mm. 


352 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Fovea  centralis  is  a  minute  central  depression  at  the  summit 
of  the  yellow  spot ;  the  diameter  is  0.2  mm.  to  0.4  mm. 

Porus  opticua  is  a  disk  at  the  point  of  entrance  of  the  optic 
nerve,  centrally  pierced  by  the  arteria  centralis  retinae,  lying 
about  jig-  inch  (3  mm.)  to  the  inner  side  of  the  yellow  spot 
and  1  mm.  below  its  level ;  it  is  the  only  portion  of  the  retina 
where  the  sense  of  vision  is  wanting,  the  hlind  spcA  ;  the  margin 
of  the  disk  is  elevated,  called  the  colh'cidus  nervi  optici. 

Pars  cilians  retinei:  consists  of  the  fibrous  and  pigmented  por- 
tions of  the  retina,  destitute  of  nerve-elements,  continued  over 
the  ciliary  processes  from  the  ora  serrata  to  the  iris ;  the 

Arteries  of  the  retina  spring  from  the  arteria  centralis  retinae, 
a  branch  of  the  ophthalmic,   which  after  piercing  the  optic 

nerve  divides  into  four  or  five 
branches,  which  soon  enter  the 
nervous  layer  of  the  retina  to 
form  a  fine  capillary  plexus  not 
extending  beyond  the  inner  nu- 
clear layer ;  no  vessels  exist  in 
the  fovea  centralis,  very  few  in 
the  macula  lutea ;  there  are  no 
anastomoses. 

Describe  the  structure  of  the 
retina. 

It  is  exceedingly  complex, 
being  composed  from  within  out- 
ward of  ten  layers,  or  properly 
eight,  two  being  boundary  lines 
(Fig.' 138). 

Membrana  limitans  interna^  a 
transparent  membrane  formed  of 
retinal  connective  tissue,  lying  in 
contact  with  the  hyaloid  mem- 
brane of  the  vitreous  humor. 

1.  Xerve-Jiher  layer,  composed 
of  continuations  of  optic  fibers 
deprived  of  their  medullary 
sheaths,  forming  radiating  bun- 
FiG.  138.-The^l^ayers^of  the  rcti.ia      ^j^^  ^^  plexuses  joining  the  next 

layer. 
2.    Ganglionic  layer,  a   single  layer  of  large  ganglion-cells, 


THE  EYE.  353 

except  at  the  macula  lutea,  where  there  are  several  layers  ;  they 
have  one  process  prolonged  into  the  fibrous  layer,  becoming  con- 
tinuous with  a  nerve-fibril,  and  one  or  more  extending  into  the 
inner  molecular  layer,  or  (according  to  some)  passing  through 
it  to  terminate  in  the  nuclear  layer. 

8.  Inner  molecnlar  or  reticular  layer ^  made  up  of  a  reticulum 
of  fibrils,  mingled  with  processes  of  the  ganglion-cells  and  those 
of  the  next  layer,  containing  in  the  interstices  minute  clear 
granules. 

4.  Inner  nuclear  layer^  containing  (1)  bipolar  cells  with  oval 
nuclei,  one  process  passing  to  the  inner  molecular  layer, 
believed  to  become  continuous  with  the  processes  of  the  gan- 
glion-cells, and  another  passing  into  the  outer  molecular  layer, 
there  bifurcating  and  (according  to  some)  communicating  with 
rod  and  cone  fibers ;  (2)  nucleated  cells  without  branches ; 
(3)  cells  connected  with  the  fibers  of  Miiller. 

5.  Outer  molecular  layer  is  thinner,  resembles  the  inner  molec- 
ular layer,  but  contains  branched  stellate  cells — probably 
ganglion-cells. 

6.  Outer  nuclear  layer  consists  of  (1)  rod-granules^  trans- 
versely striated  cells,  with  an  external  fine  process  connected 
with  a  single  rod  of  Jacob's  membrane,  and  an  internal  pro- 
longation which  enlarges,  then  breaks  iq)  into  minute  fibrils 
entering  the  outer  molecular  layer;  and  (2)  cone-granules, 
closely  connected  with  the  cones  of  Jacob's  membrane,  with  a 
thick  process  passing  inward,  becoming  bulbous  (cone-foot)  and 
terminating  by  numerous  fibrillge,  which  enter  the  outer  molec- 
ular layer. 

External  limiting  memhrane,  a  membrane  formed  of  retinal 
connective  tissue,  perforated  by  numerous  openings. 

7.  JacoVs  memhrane  or  rods  and  cones,  composed  of  rods  ar- 
ranged perpendicularly  to  the  surface,  each  composed  of  an  outer 
and  an  inner  portion  joined  by  cement-substance  ;  and  cones, 
with  apices  directed  toward  the  choroid,  formed  of  two  portions, 
and  like  the  rods  having  their  outer  segments  transversely 
striated ;  this  is  probably  the  perceptive  layer  of  the  retina. 

8.  Pigmentary  layer,  formerly  considered  a  part  of  the  cho- 
roid, consisting  of  a  single  layer  of  hexagonal,  pigmented  epi- 
thelial cells. 

The  connective  tissue  uniting  the  layers  is  a  fenestrated, 
sponge-like  structure,  the  membrane  of  MUller, 
23 


354  ESSENTIALS  OF  HUMAN   ANATOMY. 

The  Humors. 

What  is  the  aqueous  humor? 

A  small  amount  of  clear  alkaline  fluid  composed  of  water, 
96.7  per  cent. ;  albumin,  U.l  ;  sodium  chlorid  and  extractive, 
3.2  ;  filling  the  anterior  and  posterior  aqueous  chambers  of 
the  eye. 

What  are  the  anterior  and  the  posterior  aqueous  chamhers  ? 

The  anterior  chamber  is  a  space  filled  with  aqueous  humor 
bounded  in  front  by  the  cornea,  behind  by  the  front  of  the  iris, 
and  communicating  through  the  pupil  with  the 

Posterior  chamber,  also  tilled  with  aqueous  humor ;  it  is  only 
a  narrow  chink  between  the  peripheral  portion  of  the  iris,  the 
suspensory  ligament,  and  the  ciliary  processes ;  the  chambers 
are  separate  in  the  fetus. 

Describe  the  vitreous  body. 

This  forms  about  four-fifths  of  the  entire  globe,  is  trans- 
parent, of  the  consistence  of  thin  jelly,  composed  of  water,  98.5 
per  cent.,  a  few  salts,  and  a  trace  of  albumin,  and  is  enclosed 
everywhere  in  a  delicate  hyaloid  membrane,  beneath  which  are 
small,  granular,  ameboid  cells ;  it  possesses  neither  vessels  nor 
nerves,  and  has  the  fonsa  imtcllaris  in  front,  where  the  crystal- 
line lens  reposes.  Running  from  the  entrance  of  the  optic 
nerve  to  the  posterior  surface  of  the  crystalline  lens  is  the 
canal  of  StiUinr/,  or  liyaloid  canal,  filled  with  fluid  and  lined 
with  hyaloid  membrane  ;  it  once  carried  a  fetal  artery. 

Describe  the  crystalline  lens  with  its  ligaments. 

It  is  a  transparent  double  convex  body,  more  convex  pos- 
teriorly than  in  front,  enclosed  in  a  capsule,  and  is  lodged  in  a 
depression  of  the  hyaloid  membrane,  where  it  is  retained  by  its 
suspensory  ligament.  It  lies  immediately  behind  the  pupil 
surrounded  and  slightly  overlapped  by  the  ciliary  processes, 
measuring  about  one-third  of  an  inch  transversely  by  one- 
fourth  of  an  inch  antero-posteriorly,  and  is  composed  of  water, 
albuminous  matter,  fat,  and  cholesterin.  The  center  of  each 
surface  is  the  pole;  the  surfaces  meet  in  a  rounded  border, 
the  equator. 

Capsule  is  transparent,  very  elastic,  and  brittle,  measuring 
2^L_  inch  in  front,  g-gVo  ^^^^^  behind,  and  is  attached  anteriorly 


THE  HUMORS.  355 

to  the  lens  by  a  single  layer  of  polygonal  cells  ;  posteriorly  be- 
tween the  lens  and  the  capsule  this  layer  is  lacking  ;  here  fluid 
may  collect  post  mortem,  liquor  Moryagni. 

At  the  ora  serrata  the  hyaloid  membrane  splits  into  two 
layers ;  one  passes  behind  the  lens  in  front  of  the  vitreous 
humor,  which  is  completely  invested  ;  the  other  layer  continues 
over  the  ciliary  body  and  pars  ciliaris  retinae,  and  is  called  the 
zonula  of  Zinu  ;  its  free  part  extends  from  the  ciliary  body  to 
the  leUvS-capsule,  and  is  called  the  suspensori/  Ugrnnent  of  the 
lens. 

Due  to  plications  of  the  ciliary  body  over  which  the  zonula 
is  reflected  there  are  two  sets  of  fibers  in  the  suspensory  liga- 
ment; one  comes  from  the  zonula  as  it  lies  on  the  summif.s  of 
the  ciliary  processes,  and  goes  to  the  periphery  of  the  lens  and 
adjoining  part  of  its  posterior  capsule  ;  the  set  arising  from  the 
vallet/s  between  the  ciliary  processes  passes  to  the  anterior  cap- 
sule of  the  lens.  These  sets  partially  cross  each  other  at  their 
origins. 

Canal  of  Petit,  triangular  on  section,  passes  around  the  cir- 
cumference of  the  lens,  bounded  in  front  by  anterior  fibers  of 
the  suspensory  ligament,  behind  by  the  hyaloid  membrane, 
mesially  by  the  capsule  of  the  lens ;  when  inflated  it  becomes 
sacculated. 

What  is  the  structure  of  the  crystalline  lens  ? 

It  is  formed  of  numerous  laminae,  composed  of  six-sided 
fi^^^'^  5  0^0  0  ^^^^  broad  (0.005  mm.),  with  serrated  margins, 
those  of  contiguous  fibers  accurately  fitting  one  another ;  the 
lens  is  also  divisible  into  three  triangular  segments  with  their 
bases  outward.  Each  surface  shows  three  r«y.s  of  a  star  at 
angles  of  120°.  The  central  harder  portion  is  called  the  nucleus^ 
the  peripheral  portions  the  cortex  ;  it  possesses  neither  vessels 
nor  nerves. 

Describe  the  muscles  of  the  eyeball  (Fig.  139). 

Rectus  superior^:  origin,  upper  margin  of  the  optic  foramen 
and  sheath  of  the  optic  nerve ;  insertion,  sclerotic  coat  three  or 
four  lines  from  the  cornea ;  action,  turns  the  eyeball  upward 
and  inward  ;  nn-ve,  third  cranial. 

Rectus  inferior  ^ :  origin,  ligament  of  Zinn  ;  insertion,  sclerotic, 
three  or  four  lines  from  the  cornea  ;  action,  turns  the  eye  down- 
ward and  inward  ;   nerve,  third  cranial. 


356 


ESSENTIALS  OF  HUMAN   ANATOMY. 


Rectus  internus  :  origin,  ligament  of  Zinn  at  the  inner  side  of 
the  optic  foramen  ;  insertion,  the  sclerotic,  three  or  four  lines 
from  the  cornea  ;  action,  turns  the  eye  inward ;  nerve,  third 
cranial. 

Rectus  externus^:  origin,  by  two  heads,  the  upper  ^  from  the 
outer  margin  of  the  optic  foramen,  the  lower  ^  from  the  liga- 
ment of  Zinn,  and  a  pointed  bony  process  at  the  lower  margin  of 
the  sphenoidal  fissure  ;  insertion,  sclerotic,  as  the  other  recti ; 
action,  turns  the  eye  outward;  nerve,  sixth  cranial  (abducens)  ; 
between  the  two  heads  pass  the  ophthalmic  vein,  the  third, 
the  nasal  branch  of  the  fifth,  and  the  sixth  cranial  nerves. 

Obliquus  superior  ^ :  origin,  one  line  above  the  inner  margin 
of  the  optic  foramen,  terminating  in  a  rounded  tendon  which 
plays  through  a  fibro-cartilaginous  ring  or  pulley  ^  beneath  the 
internal  angular  process  of  the  frontal  bone,  whence  it  passes 
beneath  the  superior  rectus ;  insertion,  sclerotic  between  the 
superior  and  the  external  recti,  midway  between  the  cornea 
and  the  entrance  of  the  optic  nerve ;  action,  rotates  the  eye  on 


Fig.  139.— Muscles  of  the  right  orbit  (Leidy). 

its  antero-posterior  axis  and  corrects  inward  deviation  of  the 
inferior  rectus ;  nerve,  fourth  cranial  (patheticus). 

Obliquiis  inferior^":  origin,  orbital  plate  of  the  superior  max- 


THE  HUMORS.  357 

ilia ;  insertion,  sclerotic  between  the  superior  and  the  external 
recti ;  action,  rotates  the  eyeball  outward  and  corrects  inward 
rotation  of  the  superior  rectus  ;  nerve,  third  cranial. 
(For  the  muscles  of  the  lids  see  p.  142.) 

Recapitulate  the  nerve-supply  of  the  ocular  muscles. 

Third  cranial,  or  motor  oculi,  supplies  the  superior,  internal, 
and  inferior  recti,  and  the  inferior  oblique  muscles. 

Fourth  cranial,  or  patheticiis,  supplies  the  superior  oblique 
muscle. 

Sixth  cranial,  or  ahducens,  supplies  the  external  rectus 
muscle. 

Describe  the  vascular  supply  of  the  eyeball  and  its  appendages. 

(All  branches  of  the  vessels  not  supplying  these  parts  iiill 
he  omitted,  having  been  already  described  on  pages  191  to  194.) 

Ophthalmic,  arising  from  the  cavernous  portion  of  the  inter- 
nal carotid,  entering  the  orbit  by  the  optic  foramen,  giving  off 
the 

Lacrimal  to  the  lacrimal  gland,  conjunctiva,  and  upper  eye- 
lid, and  inosculating  with  the  palpebral  arteries. 

Supraorhit(d  supplies  the  levator  palpebrse  and  superior 
rectus  muscles. 

Superior  and  inferior  palpchral  supply  the  eyelids. 

Nasal  supplies  the  lacrimal  sac. 

Short  ciliary,  six  to  twelve  in  number,  penetrate  the  sclerotic 
around  the  optic  nerve  entrance  to  supply  the  choroid  and 
ciliary  processes. 

Long  ciliary,  two  in  number,  penetrate  the  sclerotic,  pass 
forward  between  it  and  the  choroid  to  supply  the  iris,  forming 
the  circnlm  iridis  major  near  the  ciliary  margin,  and  the  cir- 
cidns  iridis  minor  near  the  margin  of  the  pupil. 

Anterior  ciliary,  six  to  eight,  spring  from  the  muscular 
branches,  perforate  the  sclerotic,  and  join  the  circulus  iridis 
major. 

Arteria  centralis  retinse  obliquely  traverses  the  optic  nerve 
to  be  distributed  to  the  retina. 

Mnscnlar  branches,  one  superior,  one  inferior,  to  the  ocular 
muscles. 

Infraorhital,  from  the  internal  maxillary,  supplies  the  inferior 
rectus  and  inferior  oblique  muscles  and  lacrimal  gland. 


358  ESSENTIALS  OF  HUMAN  ANATOMY. 

What  are  the  chief  lymph-spaces  of  the  eyeball  ? 

Anterior  and  poderiur  aqueous  chambers^  spaces  of  Fontana, 
Schlemnis  and  Fetit's  canals,  If/mph-spaces  of  the  cornea  and 
iris,  hyaloid  canal, perivascular  canals  of  the  retina,  jierichoroidal 
space  between  the  choroid  and  the  sclerotic,  cavity  of  the  cap- 
sule of  Tenon  between  the  eyeball  and  the  capsule,  supravaginal 
and  intervaginal  spaces  of  the  optic  nerve. 

What  veins  return  the  blood  from  the  eye  ? 

The  superior  and  inferior  ophthalmic,  emptying  usually  by  a 
short  common  trunk  into  the  cavernous  sinus  ;  they  also  freely 
anastomose  with  the  angular  vein  of  the  face. 

Name  the  nerves  of  the  eye. 

Optic  or  second  craniid,  nerve  of  the  special  sense  of  sight. 

Motor  nerves,  the  third,  fourth,  and  sixth  cranial. 

The  ophthalmic  division  of  the  fifth  supplies  general  sensa- 
tion by  the 

Lacrimal,  to  the  same  named  gland,  conjunctiva,  and  skin  of 
the  upper  eyelid  ;  also  the  following  branches  :  frontal,  which 
gives  the  supratrochlear,  and  supraorhital,  nasal  with  its  gan- 
glionic,  long  cdiary,  and  infratrochlear  branches.  Orbital  or 
temporo-malar  nerve  from  the  second  division  of  the  fifth  also 
enters  the  orbit. 

The  sympathetic  arises  from  the  cavernous  and  carotid  plexus, 
receiving  communicating  filaments  indirectly  from  the  spinal 
nerves,  and  sending  branches  to  the  third,  fourth,  fifth,  and 
sixth  nerves ;  the  dilator  fibers  (radiating)  of  the  iris,  ciliary 
ganglion,  muscles  of  the  orbit  and  lids,  with  the  walls  of  the 
arteries,  receive  their  sympathetic  nerve-supply  from  this 
source ;  the 

Short  ciliary,  numbering  six  or  eight,  arise  from  the  ciliary 
ganglion,  subdivide  into  twelve  to  twenty  fine  filaments  and 
pierce  the  sclerotic  posteriorly  in  two  bundles,  to  ramify  in  the 
sheath  of  the  optic  nerve,  choroid,  ciliary  muscle,  iris,  and 
cornea. 

Ascending  branches  of  the  spheno-pahttine  (^MecheVs)  ganglion, 
reaching  the  orbit  by  the  spheno-maxillary  fissure,  usually 
supply  the  periosteum,  send  a  twig  to  the  optic  nerve  (Arnold), 
to  the  sixth  nerve  (Bock),  to  the  ciliary  ganglion  (Tiedemann). 


THE  APPENDAGES  OF  THE   EYE.  359 

Give  a  brief  description  of  the  optic  tracts. 

The  deep  origins  of  the  nerve-fibers  of  these  tracts  are  the 
optic  thalami,  corpora  genicuhita,  upper  pair  of  the  corpora 
quadrigemina;  which,  forming  two  flattened  bands,  wind  around 
the  crura  cerebri,  to  which  they  are  sHghtly  attached,  as  well 
as  to  the  lamina  cinerea  and  tuber  cinereum,  and  joining  in 
front  of  the  latter  they  form  the  optic  commissure  (see  pages 
241  and  242  for  illustration  and  more  elaborate  description). 

What  are  the  origin  and  course  of  the  optic  nerves  ? 

They  arise  on  either  side  from  the  optic  commissure ;  each 
passes  into  the  orbit  through  the  optic  foramen  with  the  cen- 
tral artery  of  the  retina,  which  pierces  it,  and  enters  the  eyeball 
through  the  lamina  cribrosa  yL  inch  (3  mm.)  to  the  nasal  side 
of  the  yellow  spot  and  1  mm.  below  it ;  these  nerves  are  sur- 
rounded with  a  sheath  derived  from  the  dura  mater,  between 
which  and  the  nerve  is  a  lymph-space  communicating  with 
the  subarachnoid  and  subdural  spaces. 

The  Appendages  of  the  Eye. 

(Tutamina  Oculi.) 

Name  these. 

Eyebrows^  or  mpercilia^      L(tcrim(d  gJand^  and  diicfs, 
Eyelids^  or  jjrdpebr^,  Lacrimal  sac  and  caiialiculi, 

Conjunctiva'^,  a  mucous       Nasal  duct. 
membrane, 

What  are  the  eyebrows  ? 

The  arched  eminences  of  skin  surmounting  the  upper  mar- 
gins of  the  orbits  on  each  side,  from  which  grow  several  rows 
of  short,  obliquely  placed  hairs  ;  by  the  attached  muscles  the 
eyebrows  can  partially  shut  off  light  from  the  eyes. 

What  are  the  eyelids  ? 

Two  movable;  curtains  protecting  by  their  closure  the  eyes 
from  injury  ;  the  upper  lid  is  the  larger  and  more  movable, 
having  its  own  csbivator  niuscl(\  levator  p^ilpchnr  ;  the 

l^dljx'hrid  Jissurc.  is  th(!  elliptical  space  ])etween  the  margins 
of  the  lids  when  opened,  the  internal  and  external  angles  being 
called,  respectively,  the   infrrual  and   tlu^  rxtrruai  cauflnts,  the 


360  ESSENTIALS  OF  HUMAN  ANATOMY. 

former  being  prolonged  inward,  leaving  a  triangular  space  be- 
tween the  lids,  the  htaia  lacrimalis,  at  the  commencement  of 
which  is  a  small  elevation  on  each  lid,  the  lacrimal  jxqnlla^, 
whose,  summit  is  pierced  by  a  minute  opening,  the  pinic^wm 
lacrimale^,  the  commencement  of  the  lacrimal  canal. 

What  structures  form  the  eyelids  ? 

Externally  the  skin,  beneath  which  is  much  loose  areolar 
tissue,  separating  it  from  the  fibers  of  the  orhicidaris  pa/^>e- 
hraruin  muscle.  The  lids  retain  their  shape  by  means  of  the 
so-called  tarsal  cartilages — in  reality  dense  connective  tissue 
icithout  cartilage-cells — that  for  the  upper  lid  being  half-oval 
and  the  larger,  that  for  the  lower  lid  narrower ;  these  struct- 
ures are  connected  at  their  orbital  margins  with  the  circumfer- 
ence of  the  orbit  by  fibrous  membranes,  the  tarsal  ligaments ;  the 
internal  palpehral  {tarsal)  ligament,  or  tendo  ocvli,  passes  from 
the  inner  angle  of  each  to  the  nasal  process  of  the  superior 
maxilla  ;  the  external palpehralligament  passes  to  the  malar  bone. 

Embedded  in  the  ocular  surface  of  the  cartilages  are  sebace- 
ous glands,  the  Meihomian^  discharging  their  secretion  upon  the 
free  edge  of  the  lids,  preventing  their  adhesion  ;  they  number 
thirty  or  forty  in  the  upper  lid,  are  fewer  in  the  lower  lid. 

Attached  to  the  free  margins  of  the  lids  is  a  double  or  triple 
row  of  stifi"  hairs,  curved  in  each  lid  so  that  their  convexities 
meet,  preventing  interlacing;  these  are  the  cilia.,  or  eyelashes; 
just  within  this  line  is  a  row  of  modified  sweat-glands,  the 
glands  rjf  Moll. 

The  arteries  are  two  internal  palpebrals  from  the  ophthalmic, 
two  external  palpebrals  from  the  lacrimal,  the  transverse  facial, 
and  the  superficial  temporal. 

The  nerves  are  the  third,  seventh,  and  the  sympathetic  to  the 
muscles,  the  ophthalmic  branch  of  the  fifth  to  the  skin  and  the 
conjunctiva. 

Describe  the  conjunctiva. 

It  is  a  mucous  membrane  lining  the  inner  surfaces  of  the 
eyelids  and  reflected  thence,  _/o?vnx  conjuneficae.  upon  the  ante- 
rior segment  of  the  sclerotic,  its  epithelial  layer  passing  over 
the  cornea. 

T\i&  palpehral  conjunctiva  is  thick,  opaque,  vascular,  and  cov- 
ered with  papillae,  containing  numerous  glands;  at  the  inner 


THE  APPENDAGES  OF  THE   EYE.  361 

angle  of  the  eye  it  forms  a  vertical  semilunar  fold,  the  plica 
semilunar^*.  The  folds  formed  by  the  passage  of  the  conjunc- 
tiva from  the  lids  to  the  eyeball  are  called  the  superior  and  in- 
ferior p)a^pebral  folds,  the  former  being  the  deeper  ;  they  con- 
tain numerous  convoluted  mucous  glands,  some  of  which 
resemble  lymphoid  follicles. 

The  ocular  conjunctiva  is  thin,  transparent,  possesses  few 
vessels  in  health,  and  is  loosely  attached  to  the  globe  by  the 
subconjunctival  areolar  tissue. 

The  corneal  conjunctiva  consists  only  of  epithelium. 

What  is  the  caruncula  lacrimalis^  (Fig.  141)? 

It  is  a  small,  conical,  reddish  body,  at  the  inner  canthus, 
occupying  the  space  called  the  lacus  lacrimalis,  and  is  formed 
of  a  group  of  follicles,  sebaceous  and  sweat-glands,  covered 
with  skin ;  from  the  caruncle  project  a  few  slender  hairs. 

Describe  the  lacrimal  apparatus. 

It  consists  of  the  lacrimal  gland  with  its  ducts,  the  canali- 
culi,  the  lacrimal  sac.  and  the  nasal  duct.     The 

Lacrimal  ghuuP  (Fig.  140)  is  an  oval,  compound  racemose 
gland  of  the  size  and  shape  of  an  almond,  lodged  in  a  depres- 
sion at  the  upper,  outer  portion  of  the  orbit,  its  concave  under 
surface  resting  upon  the  globe  of  the  eye,  the  conjunctiva, 
superior  and  external  recti  muscles  intervening ;  it  is  held  in 
contact  with  the  orbital  periosteum  by  a  few  fibrous  bands  ;  it 
has  two  parts,  the  smaller  one  called  the  inferior  lacrimal 
gland.     It  has  never  more  than  twelve 

Ducts'^,  opening  by  minute  orifices  in  a  row  on  the  upper  and 
outer  part  of  the  conjunctival  fornix. 

Tears  are  taken  up  by  the  puncta,  thence  passing  through 
the  canaliculi  into  the  lacrimal  sac  and  nasal  duct,  thus  reach- 
ing the  inferior  meatus  of  the  nose. 

Describe  the  canaliculi. 

They  are  two  minute  canals^  about  one-half  a  line  in  diam- 
eter, commencing  at  the  puncta ;  the  superior  passing  upward, 
then  bending  acutely  to  pass  inward  to  the  lacrimal  sac  ;  the 
inferior  passing  downward,  then  upward  and  inward  ;  they  are 
lined  with  mucous  membrane  continuous  with  the  conjunctiva, 
and  are  one-third  of  an  inch  long  (8  to  9  mm.). 


362 


ESSENTIALS  OF  HUMAN   ANATOMY. 


What  is  the  lacrimal  sac-  iFig.  141)? 

It  is  the  tlattouL'cl.  uvoidal,  sacciform  dilatation  of  the  upper 
part  of  the  nasal  duct,  lodged  in  the  groove  formed  by  the  lac- 
rimal bone  and  nasal  process  of  the  superior  maxillary  ;  its 
walls  are  formed  of  tibrous  tissue  covered  internally  by  the 


Fig.  140. — The  lacrimal  gland  and 
Meibomian  glands,  seen  from  the 
inner  surface  of  the  eyelids  (Leidy). 


Fig.  141.— The  lacrimal  apparatus, 
left  side  (Leidy). 


tensor  tarsi  muscle,  and  in  front  is  the  tendo  oculi  attached  to 
the  ridge  of  the  lacrimal  bone.  When  distended  it  is  15  mm. 
long  and  5  or  6  mm.  wide. 

Describe  the  nasal  duct\ 

It  is  a  membranous  canal  about  three-fourths  of  an  inch  long 
(12  to  24  mm.),  extending  from  the  termination  of  the  lacri- 
mal sac  through  the  osseous  nasal  duct  to  the  inferior  meatus 
of  the  nose,  passing  in  a  direction  downward,  backward,  and 
slightly  outward,  its  lumen  being  narrowest  about  the  mid- 
point :  externally  it  is  composed  of  fibro-areolar  tissue  ;  inter- 
nally, of  mucous  membrane  continuous  with  that  of  the  nose 
and  lacrimal  sac  :  the  epithelial  coating  of  the  sac  and  duct 
is  columnar  and  ciliated  only  in  spots ;  squamous  in  the  cana- 
liculi. 

What  is  the  valve  of  Hasner? 

An  imperfect  valve  of  mucous  membrane  guarding  the  some- 
what expanded  terminal  opening  of  the  duct  into  the  inferior 
meatus  of  the  nose  :  other  valvular  folds  are  less  constant. 


THE   EXTERNAL  EAR.  363 

The  Ear. 

Where  is  the  auditory  apparatus  lodged? 

In  the  petrous,  mastoid,  and  tympanic  portions  of  the  tem- 
poral bone. 

Enumerate  the  divisions. 

m  ,         7  •  •  f  Auricle,  or  pinna. 

ine  ex^erwrt/ ear,  compnsinor    .  {    rr  ^        i       i-^  ? 

T         ^         ^        y^  tiXtemal  auditory  canal. 


C  Memhrana  fympani^ 
CnvitU  of  ft/mvanum 


The  middle  ear,  or  tympanum.  \    Cavity  of  tympanum^ 

comprising ^   Mastoid  celh^ 

[^  Eustachian  tuhe. 

^   Vestibule^ 
The  internal  ear.  or  lahyrinth,  J    Semicircular  canals^ 

comprising |    Cochlea ^ 

\^  Auditory  nerve. 

The  External  Ear. 

What  is  the  auricle  or  pinna? 

Its  foundation  is  an  expanded  layer  of  fibro-cartilage.  so  dis- 
posed in  ridges  as  to  concentrate  and  direct  the  waves  of  sound 
into  the  external  auditory  meatus,  to  which  it  is  attached :  the 
cartilage  is  deficient  at  certain  points  where  it  is  connected  by 
fibrous  tissue :  it  is  covered  with  perichondrium,  outside  of 
which  is  thin,  firmly  adherent  skin,  containing  sweat-  and  se- 
baceous glands,  and  provided  with  short  downy  hairs.  The 
various  ridges  and  depressions  are  as  follows :   the 

Concha,  the  deep  cavity  leading  into  the  meatus;  the 

Tragus,  the  pointed  prominence  in  front  of  the  concha  pro- 
jecting back  over  the  meatus,  bearing  on  its  under  surface  tufts 
of  hair  ;  the 

Antifififjus,  a  small  tubercle  opposite  the  tragus,  separated 
by  a  deep  notch,  the  incisura  intertragica  ;  the 

Jlflis,  the  external  prominent  margin  of  tho  auricle  rising 
near  the  tragus  ;  the 

Antihelix,  a  parallel  prominence  anterior  to  the  former, 
rising  below  at  the  antitragus.  bifurcating  above  to  form  the 

Foss/t  of  the  aiitihelix,  a  triangular  depression  ;  the 

Fossa  of  the  helix,  the  narrow,  curved  depression  between 
the  heli.K  and  the  antihelix  (fossa  scaphoidea). 


364  ESSENTIALS  OF  HUMAN  ANATOMY. 

An  ear-pouif,  or  tubercle  of  Dane  in,  is  occasionally  seen  on 
the  postero-superior  margin  of  the  helix  pointing  forward ; 
it  is  constant  in  the  human  embryo,  and  permanent  in  many 
monkeys. 

The  inferior,  soft  pendulous  portion,  formed  of  fat  and  con- 
nective tissue  enclosed  by  integument,  is  the  lobule  of  the  ear. 

Describe  the  muscles  of  the  external  ear. 

The  attollens  aurem,  attrahens  aurem,  and  retrahens  aurem 
have  been  described  on  page  142  ;  these  are  extrinsic ;  the  in- 
trinsic are  the  muscles  of  the  auricle,  but  slightly  developed  in 
man  :  their  motor  nerve  is  the  facial. 

Helicis  major:  a  narrow,  vertical  band  on  the  anterior  border 
of  the  helix  ; 

Helicis  minor:  an  oblique  band  at  the  root  of  the  helix  from 
the  concha  ; 

Tragicus :  a  short,  vertical  band  on  the  outer  surface  of  the 
tragus  ; 

Antitragicus  :  stretching  from  the  outer  part  of  the  antitragus 
to  the  lower  part  of  the  helix  ;  these  four  muscles  are  anterior. 

Transversus  auriculae  :  radiating  from  the  posterior  surface  of 
the  convexity  of  the  concha  to  the  prominence  caused  by 
the  groove  of  the  helix  ; 

Obliquus  auris  :  a  few  fibers  passing  from  the  upper  back 
part  of  the  concha  to  the  convexity  immediately  above. 

Give  the  vascular  and  nerve-supply  to  the  auricle. 

The  arteries  are  Posterior  eiuricuhir,  from  the  external  carotid. 

Anterior  auricular,  branch  of  the  temporal. 

Auricular,  branch  of  the  occipital. 
The  veins  accompany  the  corresponding  arteries. 
The  nerves  are  Anricularis  7)iagnus,  from  the  cervical  plexus. 

Posterior  auricular,  from  the  facial. 

Auricular  branch  (Arnold's)  of  the  pneumo- 
gastric. 

Aiiriculo-temporal,    from  the  inferior  maxil- 
lary division  of  the  fifth  nerve. 

Occipitalis  major  and  minor. 

What  is  the  external  auditory  canal  ? 

It  is  an  osseo-cartilaginous,  oval,  cylindrical  canal,  w^th  its 
greatest  diameter  vertical  at  the  external  orifice,  but  reversed 


THE   MIDDLE   EAR  OR  TYMPANUM.  365 

at  the  tympanic  end ;  it  is  narrowest  at  the  middle.  About 
one  inch  long  (25  mm.),  it  is  directed  obli({uely  forward  and 
inward,  and  slightly  curved  with  its  convexity  upward,  and  is 
lined  with  thin  adherent  skin,  containing  hair-follicles  and 
sebaceous  and  ceruminous  glands  in  its  cartilaginous  portion. 
A  narrow  groove  for  the  membrana  tympani  is  at  the  inner 
end,  called  the  sulcus  tympaaicus^  interrupted  above  by  the 
notch  of  Rivinus  between  the  anterior  and  the  posterior  tym- 
panic spines. 

What  are  the  arteries  and  nerves  ? 

The  arteries  are  branches  of  the  posterior  auricular,  internal 
maxillary,  and  temporal. 

The  nerves  come  chiefly  from  the  auriculo-temporal  branch 
of  the  third  division  of  the  fifth  nerve  and  from  the  auricular 
branch  of  the  vagus. 

The  Middle  Ear  or  Tympanum. 

Describe  the  membrana  tympani. 

It  forms  the  outer  wall  of  the  tympanum,  and  is  an  oval, 
translucent  membrane  placed  obliquely  at  the  bottom  of  the 
external  auditory  meatus,  with  its  internal  surface  facing 
downward,  forward,  and  inward  at  an  angle  of  55°,with  its  long 
axis  directed  downward  and  inward ;  it  inclines  toward  the  an- 
terior and  lower  part  of  the  canal ;  at  its  upper  anterior  border 
is  a  white,  pointed  tubercle^  formed  by  the  short  process  of  the 
malleus,  while  a  yellowish-white  stripe  passing  from  this  down- 
ward and  backward  toward  the  center  indicates  the  handle  of 
the  malleus.  During  life,  when  illuminated,  the  membrana 
tympani  presents  a  triangular  light  spot  or  "  cone  of  light^'  hav- 
ing its  apex  at  the  end  of  the  malleus  handle,  whence  it  spreads 
downward  and  forward  ;  a  darker  central  portion  is  the  mnho., 
or  shadow.  The  upper  anterior  part  bridging  a  small  notch 
in  the  bony  ring  to  which  the  membrane  is  attached  (the  notch 
of  Rivinus),  is  thin,  consisting  of  loose  connective  tissue,  ves- 
sels, and  nerves,  covered  with  skin  and  mucous  membrane,  and 
has  received  the  name  of  the  membrana  flaccida^  or  Shrap- 
nelVs  membrane. 

Of  what  tissues  is  the  membrana  tympani  composed  ? 

Of  the  skin,  which  is  derived  from  the  lining  of  the  meatus; 


36G  ESSENTIALS  OF  HUMAN   ANATOMY. 

of  a  fibrous  layer,  some  of  whose  fibers  radiate  from  near  the 
center  to  the  circumference,  others  form  a  dense  ring  around 
the  attached  margin  ;  and  of  mucous  membrane,  derived  from 
that  lining  the  tympanum.  The  handle  of  the  malleus  passes 
between  the  inner  and  the  middle  layers — according  to  von 
Troltsch,  it  is  received  between  the  circular  and  the  radiating 
fibers  of  the  middle  coat ;  an  anterior  and  a  posterior  pouch 
have  also  been  described  upon  the  external  surface  opening 
downward.  The  radial  fibers  are  slightly  bowed  outward,  so 
that  between  the  depressed  umbo  and  the  attached  border  the 
membrane  is  convex  externally,  due  to  annular  fibers. 

Describe  the  arterial  supply  of  the  membrana  tympani. 

The  deejj  auricular  branch  of  the  internal  maxillary  sup- 
plies the  external  layers,  forming  a  plexus  which  communicates 
at  the  periphery  with  one  in  the  mucous  membrane  formed 
from  the 

Tympanic  hranches  of  the  internal  maxillary  and  internal 
carotid  arteries,  and  by  the 

Tynqjanic  branch  of  the  Vidian^  from  the  internal  maxillary, 
and  the 

Stylo-mastoid^  from  the  posterior  auricular. 

Mention  the  nerves  supplying  the  membrana  tympani. 

To  the  upper  portion  run  filaments  from  the  auriculo-tem- 
poral  branch  of  the  fifth,  to  the  lower  portion,  the  auricidar 
branch  of  the  vagus,  while  the  mucous  layer  is  supplied  by 
the  tympanic  plexus. 

The  Tympanum. 

Describe  it. 

It  is  an  irregular  cavity,  measuring  about  one-half  inch  an- 
tero-posteriorly,  one-third  inch  vertically,  and  one-fifth  inch 
transversely,  situated  in  the  petrous  bone,  compressed  from 
without  inward,  being  placed  above  the  jugular  fossa,  having 
the  carotid  canal  in  front,  the  mastoid  cells  behind,  the  external 
meatus  externally,  and  the  labyrinth  internally ;  it  communi- 
cates in  front  with  the  pharynx  by  the  Eustachian  tube,  and 
presents  for  examination  the  following  points  :  the 

Roof,  a  very  thin  plate  of  bone,  indicated  on  the  cranial  sur- 
face by  a  depression  on  the  anterior  surface  of  the  petrous 
portion  of  the  temporal  bone,  the  tegmen  tympani ;  the 


THE  TYMPANUM.  367 

Floor ^  narrow,  corresponding  to  the  jugular  fossa,  and  pre- 
senting near  the  inner  wall  a  small  foramen  for  Jacohsons 
nerve  ;  the 

Outer  icall,  the  membrana  tympani  and  bony  ring  to  which 
it  is  attached,  presenting  three  small  orifices,  the 

Iter  chordae  poster ixs,  opening  in  the  angle  of  the  junction 
between  the  posterior  and  external  walls,  just  behind  the 
membrana  tympani  on  a  level  with  its  center,  for  the  entrance 
of  the  chorda  tympani  nerve ;  the 

Glaserian  fissure^  'petro-tym'pamc^  just  above  and  in  front 
of  the  bony  ring,  giving  passage  to  some  tympanic  vessels, 
the  tympanic  branch  of  the  internal  maxillary  artery,  and 
lodgment  of  the  long  process  of  the  malleus ;  the 

Iter  chordse  aiiterius,  or  canal  of  Huguier^  opening  just  above 
the  preceding,  for  the  escape  of  the  chorda  tympani  nerve  ;  the 

Inner  wall  is  vertical,  looking  directly  outward,  and  presents 
the 

Fenestra  ovalls  or  oval  window,  a  kidney-shaped  opening 
leading  into  the  vestibule,  closed  by  the  base  of  the  stapes 
with  its  ligament ;  the 

Fenestra  rotunda  or  round  im'ndow,  below,  at  the  bottom  of  a 
funnel-shaped  depression,  opening  into  the  scala  tympani  of 
the  cochlea,  closed  by  the  membrana  tympani  secundaria, 
having  mucous,  fibrous,  and  serous  layers. 

Promontory,  a  rounded  hollow  eminence — the  first  turn  of 
the  cochlea — situated  between  the  oval  and  the  round  win- 
dows, and  presenting  grooves  lodging  branches  of  the  tym- 
panic plexus ;  the 

Eminence  of  the  aqnsedvctus  Fallopii  passes  above  the  oval 
window,  along  the  inner  tympanic  wall,  to  curve  behind  that 
opening  nearly  vertically  downward  along  the  posterior  wall ; 
the 

Posterior  wall  presents  the  opening  of  the  mastoid  antrum. 

Pyramid,  a  hollow  conical  projection,  behind  the  oval  win- 
dow and  in  front  of  the  vertical  portion  of  the  aquacductus 
Fallopii,  contains  the  stapedius  muscle,  whose  tendon  escapes 
from  its  summit ;  a  minute  canal  communicates  with  the  aquae- 
ductus  Fallopii,  transmitting  a  twig  of  the  facial  nerve  to  the 
stapedius  muscle  ;  the 

Ojteniny  of  the  mastoid  antrum  is  above  the  pyramid  in 
the  attic. 


368  ESSENTIALS  OF  HUMAN   ANATOMY. 

The  (interior  wall  is  wider  above  than  below,  is  related  to 
the  carotid  canal,  the  thin  bony  partition  being  perforated 
by  the  tympanic  branch  of  the  internal  carotid  artery  ;  it  pre- 
sents two  openings :  the 

Orifice  of  tlie  canal  for  the  tensor  tympani  muscle,  which  is 
situated  above,  close  to  the  Eustachian  tube,  on  the  summit 
of  a  small  conical  eminence,  the  processus  cochlearifjrniis;  the 

Opening  (f  the  Uusfachian  tube  is  immediately  below  the 
preceding,  separated  partially  by  a  thin  bony  plate,  the  sep)tum 
tubse. 

What  are  the  ossicles  of  the  tympanum  ? 

Three  bones  forming  a  movable  chain,  passing  between  the 
membrana  tympani  and  the  oval  window  (Fig.  142),  called  the 

Malleus  or  hammer,  consisting 
of  an  oval  head  articulating  with 
the  incus,  a  nech,  a  manubrium 
or  handle,  affording  attachment 
near  its  root  to  the  tensor  tym- 
pani muscle,  a  short  ])Yocess, proc- 
essus brevis,  coming  in  contact  with 
the  membrana  tympani,  and  a 
processus  gracilis  or  long  process, 
}^o^ici^a.ri  lodged  in  the  Glaserian  fissure, 

and  fastened    by   bony   or  liga- 

T?r^  T.o    rru         nu         ^*i,     mentous  attachment ;  the 
Fig.  142.— The  small  bones  of  the  ^  .#   i       •  77 

left  ear;  external  view  (enlarged)  Incus   or   anvil,  having   a  bocii/ 

(after  Gray).  articulating  with  the  malleus,  a 

long  process  terminating  in  a  rounded  end,  the  os  orbiculare, 
or  lenticular  process,  which  articulates  with  the  head  of  the 
stapes,  and  a  short  process  attached  to  the  margin  of  the  open- 
ing into  the  mastoid  cells  ;  the 

Stapes  or  stirruj)  consists  of  a  head  articulating  with  the  os 
orbiculare,  a  neck  receiving  the  insertion  of  the  stapedius  mus- 
cle, two  branches  or  crura  joining  the  oval  base,  which  latter  is 
connected  with  the  margins  of  the  oval  window  by  ligamentous 
fibers. 

Describe  the  ligaments  of  the  ossicles. 

The  suspensory  ligament  of  the  malleus,  passing  between  the 
tympanic  roof  and  the  head  of  the  malleus  ;  the  anterior  liga- 


THE  TYMPANUM,  369 

ment  of  the  mallens  goes  from  its  neck  to  the  anterior  wall  near 
the  Glaserian  fissure  ;  the  external  ligament  of  the  malleus,  fan- 
shaped,  converges  from  the  margin  of  the  notch  of  liivinus  to 
the  processus  brevis. 

The  posterior  lujament  of  the  ineiis,  passing  between  the  pos- 
terior tympanic  wall  near  the  margin  of  the  opening  into  the 
mastoid  cells  and  end  of  the  short  process  of  the  incus;  the 
suspensor)/  ligament  of  the  incus,  descending  from  the  tympanic 
roof  to  the  incus,  near  its  articulation  with  the  malleus  ;  the 

Annular  ligament  of  the  stapes,  connecting  the  circumference 
of  its  base  to  the  margins  of  the  oval  window  ;  the 

Capsular  ligaments,  around  the  articulations  between  the 
incus  and  the  malleus,  os  orbiculare  and  stapes,  these  joints 
having  their  surfaces  coated  with  hyaline  cartilage  and  being 
provided  with  synovial  membranes. 

Other  ligaments  have  been  described  under  special  names,  as 
accessory  anterior  and  inferior  ligaments  of  the  malleus,  and 
the  obturator  ligament  of  the  stapes,  this  latter  being  a  mem- 
brane filling  up  the  opening  between  the  crura  of  the  stapes. 

Describe  the  muscles  of  the  tympanum. 

Only  two  are  well  recognized.  Sommering  described  four, 
others  have  mentioned  still  more  ;  but  further  research  proves 
them  to  be  ligamentous  or  fascial ;  the  major  and  minor  laxator 
tympani  muscles  are  now  described  as  ligaments  of  the  malleus. 

Tensor  tympani :  origin,  under  surface  of  the  petrous  bone,  ad- 
joining portion  of  the  cartilaginous  Eustachian  tube,  its  own 
osseous  canal ;  it  makes  a  sharp  bend  outward  around  the  end 
of  the  processus  cochleariformis  ;  insertion,  handle  of  the  mal- 
leus near  the  root ;  action,  draws  the  membrana  tympani  in- 
ward— /.  e.  increases  tension  ;  nerve,  by  a  twig  to  the  internal 
pterygoid  muscle  through  the  otic  ganglion. 

Stapedius:  origin,  from  the  interior  of  the  pyramid  ;  insert  i(m, 
neck  of  the  stapes;  its  tendon  may  contain  a  bony  spine;  ac- 
tion, compresses  the  contents  of  the  vestibule;  it  pushes  the 
hinder  part  of  the  base  of  the  stapes  into  the  vestibule  and 
draws  the  fore  part  from  it ;  nerve,  filament  of  the  facial. 

Describe  the  arterial  supply  of  the  tympanum. 

These  arteries  are  about  six  in  number ;  two  are  large,  and 
form   a  vascular  circle  on  the  margin  of  the  membrana  tym- 
2t 


370  p:ssentials  of  human  anatomy. 

pani.  The  ti/mpanic  hranch  of  the  internal  maxillary  enters 
by  the  (llaserian  fissure  and  is  distributed  to  the  niembrana 
tympani,  joining  the 

Sff/I(>-ni(t.'ifoi(/,  from  the  posterior  auricular  to  the  back  part 
of  the  tympanum  and  mastoid  cells.  This  enters  by  the  stylo- 
mastoid foramen.  Other  small  branches  are  the  2:>etrosaI,  from 
the  middle  meningeal,  entering  through  the  hiatus  Fallopii ; 
the 

Tj/mpanic,  from  the  internal  carotid,  perforating  the  thin 
bony  wall ;  the 

Tympanic  hranch  of  tlic  Vidian,  from  the  internal  maxillary 
and  a 

Branch  from  the  ascending  pharyngeal,  both  by  the  Eusta- 
chian tube. 

What  nerves  supply  the  tympanum? 

The  tympanic  hranch  of  the  gl<n:i>(>-p>]air}jn(jcal  (Jacobson's 
nerve),  which  pierces  the  floor  of  the  tympanum,  and  aids  in 
forming  the  tympanic  ph-xus,  which  supplies  the  fenestras, 
mucous  membrane,  and  Eustachian  tube  ;  the 

Tympanic  hranch  of  the  facial,  supplying  the  stapedius 
muscle  ;  the 

Branch  from  the  otic  ganglion,  supplying  the  tensor  tympani 
muscle. 

(The  chorda  tympani  from  the  facial,  passing  into  the  tym- 
panum by  the  iter  chordae  posterius,  emerging  by  the  iter 
chordae  anterius,  arching  across  the  cavity  between  the  handle 
of  the  malleus  and  the  long  process  of  the  incus  ;  it  is  covered 
with  mucous  membrane  and  gives  off  no  branches.) 

Describe  the  formation  of  the  tympanic  plexus. 

The  plexus  occupies  shallow  grooves  on  the  inner  wall  of 
the  middle  ear,  especially  on  the  promontory,  and  is  formed  by 
(1)  Jacohsons  nerve  from  the  petrosal  ganglion  of  the  glosso- 
pharyngeal ;  (2)  the  small  deep  petrosal  (carotico-tympanicns 
snperior^  runs  in  the  processus  cochleariformis,  enters  the 
foramen  lacerum  (middle  lacerated),  and  joins  the  sympathetic 
plexus  on  the  carotid  artery  ;  (3)  a  branch  joins  the  great 
superficial  petrosal  nerve  in  the  hiatus  Fallopii ;  (4)  the  small 
superficial  petrosal  receives  a  filament  from  the  geniculate  gan- 
glion of  the  facial  and  passes  to  the   otic  ganglion  ;   (5)  the 


THE  TYMPANUM.  371 

carotico-tympanicus  inferior  is  a  sympathetic  twig  (or  twigs) 
passing  up  from  the  carotid  plexus  to  the  tympanic  plexus. 

Describe  the  Eustachian  tube. 

It  is  about  one  and  one-half  inches  (36  mm.)  long,  passing 
downward  at  an  angle  of  30°  from  the  horizontal,  forward  and 
inward  at  an  angle  of  45°,  the  passage  by  which  the  air  in  the 
middle  ear  freely  communicates  with  that  in  the  pharynx,  thus 
permitting  equal  pressures  on  the  tympanic  membrane.  It  con- 
sists of  about  one-third  bone  and  two-thirds  fibro-cartilage  and 
fibrous  tissue ;  their  point  of  junction  is  the  narrowest  part  of 
the  tube,  the  isthmus  tiibae. 

The  osseous  2^0  ft  ion  is  one-half  inch  long,  commencing  at  the 
lower  part  of  the  anterior  tympanic  wall,  gradually  narrowing 
to  terminate  at  the  angle  of  junction  of  the  petrous  and 
squamous  portions  of  the  temporal  bone. 

The  cartilaginous  portion  is  about  one  inch  long,  formed  by 
a  triangular  plate  of  elastic  fibro-cartilage  curved  upon  itself 
into  a  partial  tube  ;  but  inferiorly  the  margins  are  not  in  con- 
tact, the  defect  being  filled  by  fibrous  and  muscular  tissue. 

The  mucous  membrane  is  continuous  with  that  of  the  phar- 
ynx, and  is  covered  with  ciliated  epithelium,  thick  below  and 
thin  above. 

Where  is  the  pharyngeal  orifice  situated? 

At  the  upper  lateral  portion  of  the  pharynx  behind  the  in- 
ferior turbinated  bone,  above  the  level  of  the  nasal  floor. 

Has  this  tube  any  special  muscles? 

Spheno-staphylinus :  origin,  spine  of  the  sphenoid  and  the  car- 
tilaginous tube ;  insrrfion,  pharyngeal  aponeurosis,  or  soft  palate, 
palate  bone  near  the  posterior  nasal  spine,  or  hamular  process; 
nerve,  probably  the  pharyngeal  plexus  through  the  spinal  ac- 
cessory ;  acfioii,  lifts  the  palate  or  dilates  the  tube. 

Salpingo-pharyngeus :  a  thin  layer  bcnieath  the  mucous  mem- 
brane, rising  from  the  cartilage  of  the  tube,  passing  to  the 
palato-pharyngcus  muscle  ;   nerrc.  and  action  as  given  above. 

Jiare  niusc/rs  :  pterygo-salpingoideus,  petro-stujdiylinus,  pal- 
ato-staphylinus,  glosso-staphylinus.  The  levator  and  tensor 
palati   muscles  dilate  the  tube. 


372  ESSENTIALS  OF  HUMAN   ANATOMY. 

Give  the  arterial  and  nerve-supply  of  the  Eustachian  tube. 

Tlie  <(scciuh'u(/  pluLi\ijn<j<'al^  iVoiu  the  external  carotid. 

Branches  of  the  middle  ineiiiiujeal^  from  the  internal  maxil- 
lary. 

Branch  from  the  sf^lo-rn/istoid  artery. 

The  nerves  are,  in  addition  to  those  supplying  the  muscles 
of  the  tube  (supra),  from  the  Ji/th  and  seventh  pairs  and  the 
spinal  accessory. 

The  Internal  Ear,  or  Labyrinth. 

Name  its  divisions. 

m  1  1      •  ,1  •  .     C    Vestibule^  (Ficr.  143), 

ihe  osseous  laounnth,  consist-   \     ci      •  •       ?  i  ((i^ 

(}  X    ^semicircular  canals  ,' 


ing  of 


(^  Cochlea* 


^  Utricle, 

rr,,  ,  7  7      •  ,7  31embranous  semicircular 

Iha  membranous  labyrinth,  con-  , 

•  ^-         n  ^         canals. 


sisting  of 


^Saccule, 
Membranous  cochlea. 


The  internal  auditory  canal,  at  the  bottom  of  which  is  the 
lamina  cribrosa,  for  the  passage  of  the  auditory  nerve  and  ves- 
sels and  the  facial  nerve. 

The  auditory  nerve.,  eighth  cranial  ( portio  mollis),  is  the  spe- 
cial nerve  of  hearing,  distributed  only  to  the  internal  ear. 

The  organ  of  Corti  is  what  the  retina  is  to  the  eye,  viz.  the 
terminal  and  receptive  apparatus. 

Describe  the  internal  ear. 

It  is  formed  by  a  series  of  cavities  excavated  in  the  petrous 
bone,  communicating  externally  with  the  middle  ear  by  the 
round  and  oval  windows,  internally,  with  the  internal  auditory 
canal ;  within  the  osseous  labyrinth,  surrounded  by  the  peri- 
lymph, is  the 

Membranous  labyrinth — filled  with  endolymph — upon  which 
the  auditory  nerve-filaments  are  distributed. 

Describe  the  various  subdivisions  of  the  osseous  labyrinth. 

The  vestibule  is  the  common  central  cavity  with  which  all 
parts  of  the  internal  ear  communicate,  placed  behind  the  coch- 


THE   INTERNAL   EAR,   OR   LABYRINTH. 


373 


lea,  in  front  of  the  semicircular  canals,  at  the  inner  side  of  the 
tympanum  ;  it  is  ovoid,  measuring  about  one-fifth  of  an  inch 
(5  mm.)  from  before  backward,  as  well  as  from  above  down- 
ward, less  from  without  inward,  and  presents 

The  fenestra  ovah's,  on  its  outer  wall,  closed  in  the  fresh 
state  by  the  base  of  the  stapes  and  its  ligament. 

The  fovea  heinisjiherica'^,  a  small  circular  depression  on  its 
inner    wall,    perforated    antero-inferiorly    by    several    minute 
foramina  for   the  auditory  nerves  to 
the   saccule ;   the  perforated  plate  is 
called  the  macula  cribrosa. 

The  crista  vestibuli  is  a  vertical 
ridge  behind  the  macula  cribrosa  ;  its 
anterior  part  is  the  pyramidal  emi- 
nence; below,  the  crista  divides  and 
encloses  the  fossa  cocldearis  pierced 
by  nerve-fibers. 

The  aqvseductas  vestihnli,  at  the 
back  part  of  the  inner  wall,  trans- 
mitting a  small  vein,  and  the  ductus 
endolymphaticus.  a  tubular  prolonga- 
tion of  the  lining  membrane  of  the  vestibule,  ending  in  a 
pouch  in  the  cranial  cavity  between  layers  of  the  dura  mater. 

The  fovea  hemielliptica^,  a  transversely-oval  depression  on 
the  roof,  separated  by  the  crista  vestibuli  from  the  fovea  hemi- 
sph  erica. 

The  orifices  of  the  semicircular  canals^,  five  in  number,  open 
behind. 

The  apertura  scalse  vestihidi  cocldese  is  situated  anteriorly. 


Fig.  143.— The  left  osseous 
labyrinth  laid  open  ;  exter- 
nal" view  (enlarged)  (Leidy). 


Describe  the  semicircular  canals  S''',^ 

They  are  three  curved  bony  tubes,  each  describing  the  greater 
part  of  a  circle  or  ellip.sc,  of  unequal  lengths,  of  a  diameter  of 
-^^  inch  (1.5  mm.),  each  lying  at  a  right  angle  to  the  other  two 
and  presenting  at  one  end  a  dilatation,  or  ampulla,  nearly 
double  the  diameter  of  the  tube  (2.5  mm.)  ;  the 

Superior  semieircuhir  c<tnal^  is  vertical,  describes  about  two- 
thirds  of  a  circle,  passes  nt  right  angles  to  the  posterior  surface 
of  the  petrous  bone,  and  forms  a  projection  upon  its  anterior 
surface;  it  is  20  mm.  long;  its  outer  end  is  its  ampulla.,  open- 


374 


esse:ntials  of  human  anatomy. 


ing  separately  into  the  vestibule  ;  its  inner  undilated  extremity 
joins  with  that  of  the 

Pitsferior  aemicircnlar  caiuiP^  opening  by  a  common  orifice 
at  the  back  of  the  vestibule  ;  this  canal  is  also  vertical,  is  nearly 
parallel  to  the  posterior  surface  of  the  petrous  bone,  and  is  the 
longest  (22  mm.),  the  dilated  extremity  opening  at  the  lower 
back  part  of  the  vestibule ;  the 

External^  or  horizoufal  semicircular  canal\  is  the  shortest 
(15  mm.),  and  is  directed  outw^ard  and  backward  ;  its  ampullated 
end  opens  into  the  vestibule  just  above  the  oval  window,  its 
other  extremity  by  a  separate  orifice  at  the  upper  back  part  of 
the  vestibule. 


Describe  the  cochlea. 

The  cochlea^  (Fig.  144)  is  conical,  somewhat  resembles  a  snail- 
shell,  and  forms  the  anterior  part  of  the  labyrinth  ;  it  is  placed 

almost  horizontally  in  front  of  the 
vestibule,  its  apex  directed  out- 
ward, forward,  and  downward,  its 
base  corresponding  to  the  internal 
auditory  meatus ;  its  length  is  5 
mm.,  and  breadth  at  base  9  mm. 
A^iewed  from  its  base,  the  right 
cochlea  is  coiled  clockwise ;  it 
presents  the 

Modiolus^  a  central  conical 
axis,  perforated  by  numerous 
canals  for  filaments  of  the  coch- 
lear branch  of  the  auditory  nerve, 
its  apex  terminating  in  a  delicate 
expanded  lamella,  like  a  funnel  divided  longitudinally,  called 
the  in/undihidiim ;  extending  from  base  to  apex  is  a  canal,  the 
canaJis  ccnfralis  modioli,  for  a  small  nerve  and  artery.  Making 
two  and  one-half  (two  and  three-fourths,  Quain)  spiral  turns 
around  the  modiolus  is  the 

iSpiral  canal^,  about  one-twelfth  of  an  inch  (2  mm.)  in  diam- 
eter, and  one  and  one-third  inches  (33  mm.)  long,  narrowing 
from  base  to  apex,  there  forming  the  cupola,  where  the  scala 
tympani  and  scala  vestibuli,  formed  by  the  lamina  spiralis, 
communicate  by  the  helicotrema. 


Fig.  144.— The  left  cochlea  laid 
open  (enlarged)  (Leidy). 


THE  INTERNAL   EAR,   OR   LABYRINTH.  375 

The  coclilea  presents  three  openings :  the  fenestra  rotunda, 
connecting  the  scala  tympani  with  the  middle  ear,  an  oval 
opening  from  the  scala  vestibuli  into  the  vestibule,  and  that 
of  theaqucneductiis  cochleae ^  for  an  emissary  vein;  projecting 
from  the  modiolus  is  the 

Lamina  spiralis"  (Fig.  144),  a  process  formed  of  two  bony 
lamella?,  between  which  are  numerous  canals  for  nerve-fibers, 
defective  in  the  last  half  turn  of  the  cochlea,  leaving  an  aperture, 
the  helicotrema,  and  terminating  by  the  hook-like  hamiilar 
2)rocess'']  winding  around  the  modiolus  at  the  point  of  attach- 
ment of  the  lamina  spiralis  is  the  canalis  spiralis  modioli,  lodg- 
ing the  enlargement  of  the  cochlear  nerve  containing  ganglion- 
cells,  called  theffanglion  spirale,  whence  come  the  nerve-branches 
to  the  organ  of  Corti. 

What  is  the  scala  vestibuli '"  (Fig.  144)? 

It  is  that  portion  of  the  canal  of  the  cochlea  above  the  lamina 
spiralis  and  membrane  of  Reissner,  communicating  with  the 
vestibule  below  and  the  scala  tympani  above,  by  the  helico- 
trema ;  it  is  filled  with  perilymph. 

Describe  the  scala  tympani  «^ 

It  is  that  portion  of  the  spiral  canal  below  the  lamina 
spiralis  and  the  membranous  cochlea,  terminating  below 
at  the  round  window— which  is  closed  by  a  membrane,  the 
memhrana  tympani  secundaria — and  communicating  above 
with  the  scala  vestibuli  at  the  helicotrema  ;  it  is  filled  with 
perilymph. 

What  is  the  aquseductus  cochleae  '^  ? 

A  small  canal  transmitting  a  vein  from  the  cochlea  to  the  in- 
ferior petrosal  sinus,  commencing  at  the  lower  wall  of  the  scala 
tympani,  and  ending  to  the  inner  side  of  the  carotid  canal  on 
the  inferior  surface  of  the  petrous  bone. 

Describe    and   name   the    subdivisions   of  the   membranous 
labyrinth  (Fig.  145). 
It  consists  of  a  series  of  closed  membranous  sacs  containing 

eiidolympli ;   its  various  parts  are  called 

_-,'  „    ,  ,    .  r.    ,1      (  Utricle,  ]  two    membra- 

The  vestihnle,  consisting   of    the  |  ^v,v,^.^.„^,^  |      ^^^^  .^es, 

with  the  former  of  which  communicate  the  three 


376  ESSENTIALS  OF  HUMAN   ANATOMY. 

Memhranons  semicircular  cannh. 

The  utricle  and  saccule  are  separate,  but  are  indirectly  con- 
nected by  a  minute  canal  passing  from  the  saccule  to  a  similar 
one  from  the  utricle,  forming  the  endolymphatic  duct  which 
passes  along  the  aquaeductus  vestibuli  to  end  by  a  blind  pouch 
on  the  posterior  surface  of  the  petrous  bone ;  the  saccule  com- 
municates with  the  scala  media  by  the  caiiah's  reimiens.  The 
endolymph  in  all  parts  thus  communicates  freely. 

Describe  the  utricle. 

It  is  an  oblong,  laterally  compressed  sac,  filled  with  endo- 
lymph, placed  in  the  upper  back  part  of  the  vestibule  in  the  fovea 
hemielliptica,  communicating  behind  w^ith  the  membranous  semi- 
circular canals  by  five  openings,  and  has  distributed,  chiefly  at 
one  part  of  its  walls,  numerous  branches  of  the  auditory  nerve, 
at  which  point  is  a  round  mass  of  minute  crystals  of  calcium 
carbonate,  bound  together  by  delicate  fibrous  tissue  forming 
the  otolithic,  otoconia^  or  ear-stohes  ;  the  thickening  of  the  wall 
both  of  the  utricle  and  saccule,  where  the  nerves  penetrate, 
is  called  the  mucvla  acustica. 


.^ 


Ductus 
£fido-iynij>AatieaS 


C^ 


Fig.  145.— The  right  membranous  labyrinth  ;  external  view  (enlarged)  (Gray). 


What  are  the  membranous  semicircular  canals  ? 

They  are  three  canals  of  the  same  shape,  but  one-fifth  to  one- 
third  the  diameter  of  the  containing  osseous  canals,  to  which 
they  are  fastened  by  numerous  fibrous  bands  ;  their  five  ori- 
fices open  into  the  utricle.  Each  has  three  coats,  Jihrons^  tunica 
propria,  and  an  epithelial  lining. 


THE   INTERNAL   EAR,   OR   LABYRINTH. 


^77 


Describe  the  saccule. 

It  is  a  globular  sac,  smaller 
than  the  utricle,  to  which  it 
is  attached  at  one  point,  and 
lies  in  the  fovea  hemispherica; 
it  is  surrounded  with  peri- 
lymph, and  indirectly  com- 
municates by  a  short  canal 
with  the  utricle  and  with  the 
membranous  cochlea  or  scala 
media  by  the  caualis  reiiniens 
of  Hensen,  a  funnel-shaped 
duct,  1  mm.  long,  and  0.5  mm. 
wide.  The  saccule  is  3  mm. 
d    2    mm.    broad  ;    it 


Fig.  146.— Section  of  the  first  turn  of 
the  cochlea,  showing  the  three  scalse 
(enlarged;.  (Leidy; 


an 


contains  a  small  bundle  of  otoliths ;  numerous  nerves  open  on 
its  floor  upon  a  macula. 

What  is  the  membranous  canal  of  the  cochlea"  (Fig.  146)? 

More  usually  called  the  scala  iiiedia^  caualis  coclilese^  or  the 
ductus  cochlearis^  it  begins  by  a  blind  extremity  at  the  lower 
anterior  portion  of  the  vestibule,  enters  the  cochlea,  where  it 
forms  in  cross-section  a  triangular  canal,  its  base  being  the 
outer  wall  of  the  cochlea,  its  lower  wall  the  memhrana  hasil- 
ori'.s'',  its  upper  the  membrane  of  Reissner'^  \  it  is  filled  with 
endolymph  and  contains  the  organ  of  On-ti"",  covered  by  the 
delicate  memhrana.  tectorial  parallel  with  the  basilar  membrane**. 
The  periosteum  on  the  upper  surface  of  the  osseous  spiral 
lamina  forms  an  elevation,  the 

Limhus  lamina,  spiralis  "%  which  presents  an  upper  and  a  lower 
margin  called  respectively  the  lahiam  vestihnlare  and  lahium 
tijmpanicum,  the  groove  formed  between  these  being  termed 
the  sulcus  spiralis^,  shaped  like  the  letter  C. 


What  is  the  membrane  of  Reissner ''  ? 

A  delicate  membrane  stretched  between  the  outer  wall  of 
the  cochlea  and  the  periosteum  of  the  vestibular  surface  of  the 
osseous  spiral  lamina  near  the  commencement  of  the  Umbus 
lamin;«  spiralis"',  forming  the  upper  wall  of  the  scala  media. 


378  ESSENTIALS  OF  HUMAN  ANATOMY. 

What  is  the  membrana  basilaris ''  ? 

A  thin  membrane  passing  from  the  labium  tympanicum  to 
the  wall  of  the  cochlea,  where  it  expands  into  the  triangular 
llgamoitum  sptrult^"^.  It  forms  a  part  of  the  floor  of  the  scala 
media,  supporting  on  its  upper  surface  the  organ  of  Corti ''". 

Describe  the  membrana  tectoria  or  membrane  of  Corti '. 

A  delicate  membrane  rising  from  the  upper  surface  of  the 
limbus  near  the  attachment  of  the  membrane  of  Ileissner "", 
passes  over  the  superior  labium,  and  dips  down  into  the  spiral 
groove  like  a  pad  ;  it  runs  nearly  parallel  with  the  basilar  mem- 
brane**, rests  upon  the  organ  of  Corti'"",  and  ends  in  the  outer 
hair-cell  region. 

Describe  the  organ  of  Corti''  (Fig.  147). 

It  consists  of  a  complex  body  formed  by  a  series  of  some 
three  thousand  arches  roofing  over  a  space  called  the  zona 
arcuata.  formed  of  rods  and  epithelial  hair-cells,  lying  upon 
the  membrana  basilaris*"  and  covered  by  the  membrana  tectoria' ; 
the 

Rods  of  Corti  are  disposed  in  two  rows,  the  inner  ^^  and 
outer  ^^  ?-ofZ.s,  each  rod  with  its  swollen  base  resting  upon  the 
basilar  membrane'',  and  its  expanded  upper  end  inclined  toward 
and  in  contact  with  the  opposite  one,  forming  an  arched  canal ; 
the  upper  end  of  the  inner  rod  resembles  the  upper  end  of  the 
human  ulna  ;  the  same  end  of  the  outer  rod  resembles  a  swan's 
head ;  there  are  about  5600  inner  rods,  4000  outer  rods ; 
hasilar  celh  occupy  the  angle  between  the  base  of  each  rod 
and  the  basilar  membrane. 


Fig.  147.— a  pair  of  rods  of  Corti,  from  the  rabbit  (highly  magnified)  (Leidy). 

Hdir-cens"^  (Fig.  148)  are  epithelial  cells  with  stiff  hair-like 
cilia /5  ;  outer  hair-cells,  external  to  the  outer  rods"',  present  four 
rows,  numbering  about  12,000  ;  inner  hair-cells  present  a  single 


THE   I^TER^:AL   EAR,   OR   LABYRINTH. 


379 


row  internal  to  the  inner  rods*"^,  numbering  about  P>500.  Each 
hair-cell,  outer  or  inner,  has  about  20  hairlets.  Beneath  and 
between  the  hair-cells  are  the  cells  of  Dieters^  each  expanding 
into  2l  phalangeal  process  ;  the 

Lamiaa  reticularis  is  formed  of  several  rows  of  small 
fiddle-shaped  cuticular  structures  called  phalanges^  con- 
nected together  and  to  the  heads  of  the 
outer  rods,  forming  rings °'°'',  through 
which  project  the  hairs  of  the  outer  hair- 
cells. 

Describe  the  auditory  nerve. 

Its  snperjjcial  origin  is  by  two  roots, 
wcs/«/,  from  the  groove  between  the  olivary 
and  restiform  bodies  at  the  lower  border 
of  the  pons  (page  246)  ;  the  other,  lateral, 
winds  around  the  restiform  body  appar- 
ently connected  with  the  auditory  stri^. 
It  enters  the  internal  auditory  canal  with 
the  facial  nerve,  and  at  its  end  divides 
into  an  upper  vestihular  portion  which 
comes  from  the  mesial  root  only,  and  a 
loirer  portion  which  belongs  wholly  to 
the  lateral  root  and  passes  through  the 
foramina  below  the  crista  falciform  is ;  it 
gives  off  a  posterior  brancli  and  the  coch- 
lear nerve. 

It  is  here  necessary  to  mention  some  of 
the  bony  parts  involved.     The  end  of   the  internal  auditory 
canal  is  the  lamina  cribrosa,  transmitting  the  nerves  as  seen' 
in     the     diagram     (Fig.     149). 
Crista    falcifonnis    runs    across 
the   l((min(f,  separating   a  small 
superior  fossa  from   a   large  in- 
ferior one.     The  upper  fossa  is 
the  frrea  crihrosa  superior  ;  ante- 
rior to   it   is   the   orifice  of  the 
aquoL'ductus  Fallopii  for  the  en- 
trance of  the  facial  nerve.     The  inferior  fossa  shows  posteriorly 
(1)  area  crihrosa  media,  (2)  foramen  singnlare,  anteriorly  (X») 


Fig.  148.— View  of  a 
small  partofthelnnnan 
organ  of  (orti,  from 
above  (highlj*  magni- 
fied). 


CristaFcdcif - 
/br.Cent.CocA 


SpirHr 


Jr.CriUufe. 

■Jr.CrikMecL 
for.Sinq. 


Fro.  149.— Fnndu.s  of  the  riglit  in- 
ternal anditory  meatus  ((iuain). 


380  ESSENTIALS  OF  HUMAN   ANATOMY. 

tractus  spiraJii^  foramiituleufus,  ending  in  the  foramen  centrale 
cocldesfL  for  the  cochlear  nerve. 

The  vestibular  division  of  the  auditory  nerve  splits  into  fila- 
ments which  pass  through  the  area  cribrosa  superior^  and  enter 
the  vestibule  through  the  macula  cribrosa,  to  be  distributed  to 
the  utricle  and  the  ampullae  of  the  external  and  superior  semi- 
circular canals. 

The  inferior  division  by  its  posterior  branch  sends  twigs 
through  the  area  cribrosa  media  and  the  openings  of  the 
fovea  hemispherica  to  supply  the  saccule ;  it  sends  another 
branch  through  the  foramen  singidare  to  the  ampulla  of  the 
posterior  semicircular  canal ;  the 

Cochlear  nerve  divides  into  numerous  filaments  at  the  base 
of  the  modiolus  which  enter  its  canals,  pass  between  the  two 
plates  forming  the  lamina  spiralis,  forming  a  plexus  which  con- 
tains ganglion-cells,  and  sends  branches  to  supply  the  inner  and 
outer  hair-cells ;  the 

Intumescentia  ganglioformis  Scarpse  is  on  the  vestibular 
branch  in  the  internal  auditory  canal ;  the  two  ganglia  of 
Corti  are  on  the  nerve  to  the  posterior  ampulla. 

The  ganglion  sjyirale  is  on  the  cochlear  nerve  in  the  canalis 
sjiira/is  modioli. 

The  branches  of  the  auditory  nerve  and  the  apertures  by 
which  they  leave  the  meatus  are  shown  in  the  following  table : 

o         .      J.   .  .  TTo  utricle  ")    .  ., 

feuperior  division  or  i  rp  •  n     f  Area  cribrosa 

^^•11  ^  Lo  superior  ampulla  y 

vestibular  nerve  .  j  m        i        i  n     I       superior. 

(^  io  external  ampulla  J  ^ 


Inferior 
division 


r  rr  1  f  Area  cribrosa 

.  T^    ^     .  io  saccule  <  -,• 

J  Posterior  J  (       media. 

1      branch  ]  m  ,     •  n     f  Foramen  sin- 

'^  io  posterior  ampulla  <  , 

^  (       gulare. 

n    ■l^        (  Tractus  spiralis  foraminu- 
Cochlear  i      i     ,  i  x» 

■s      lentus  and  toramen  cen- 
nerve    j      .     ^  ^  ^ 

(^     trale  cochlea. 

Give  the  arterial  supply  of  the  labyrinth. 

The  internal  auditory,  a  transverse  branch  of  the  basilar, 
enters  with  the  nerve  the  internal  auditory  canal,  there  to  di- 
vide into  a  vestibuhr  and  a  cochlear  branch  ;  the  sti/Io-mastoid, 
from  the  posterior  auricular ;  occasionally  branches  from  the 
occipital. 


THE  ANATOMY  OF   INGUINAL  HERNIA.  381 

THE   ANATOMY   OF    INGUINAL    HERNIA. 

What  is  the  inguinal  canal? 

The  canal  passing  downward  and  inward  fur  one  and  one-half 
inches  (3.5  cm.),  which  lodges  the  spermatic  cord  in  the  male, 
the  round  ligament  in  the  female,  pursuing  a  course  nearly 
parallel  to  Poupart's  ligament  through  or  between  the  abdom- 
inal muscles,  commencing  at  the  internal  abdominal  ring  and 
terminating  at  the  external  abdominal  ring*^  (I'ig-  150). 

Describe  the  internal  abdominal  ring. 

It  is  an  ovoidal  opening  in  the  transversalis  fascia ^^  midway 
between  the  anterior  superior  iliac  spine  and  the  symphysis 


■'"  iiKi'i'jfcv        \\\\«ii«i>;    W/u','"^'!AJ '/'/'■ 


Fig.  150.— The  anatomy  of  inguinal  and  femoral  hernia  (Leidy). 

pubis,  about  half  an  inch  above  Poupart's  ligament*^.  It  is 
bounded  above  and  externally  by  arched  fibers  of  the  trans- 
versalis muscle"*,  below  and  internally  by  the  epigastric  ves- 
sels''*; from  its  circumference  passes  the  iii/nndibuUf arm  fascia 
on  to  the  spermatic  cord  or  round  ligament. 

What  is  the  external  abdominal  ring"? 

An  obli((uely  triangular  ojxining  in  the  aponeurosis'^  of  the 
external  oblifjue  muscle',  just  above  the  crest  and  to  tlie  inner 
side  of  the  spine  of  the  piibes;  from  base  to  apex  it  averages  one 
inch,  by  half  an  inch  transversely.      It  is  bounded  below  by  the 


382  ESSENTIALS  OF  HUMAN   ANATOMY. 

crest  of  the  pubes,  above  and  in  front  by  the  curved  interco- 
lumiuir  jihcrs''  and  on  each  side  by  the  free  borders  of  the  apo- 
neurosis called  the  internar"  and  external  columns^  or  pillars  of 
the  ring  ;  from  the  margins  of  the  ring  passes  on  to  the  cord 
or  round  ligament,  the  inf ercol inu nar  fascia . 

Give  the  boundaries  of  the  inguinal  canal. 

Anteriorly,  the  skin,  superticial  fascia,  the  aponeurosis  of  the 
external  oblique  throughout,  and  the  outer  third  of  the  internal 
oblique  muscles. 

Posteriorly,  the  triangular  fascia  of  the  abdomen,  conjoined 
tendon ^^  of  the  internal  oblique  and  transversalis  muscles, 
transversalis  fascia ^^,  subperitoneal  tissue,  and  peritoneum. 

Superiorly,  the  arched  fibers  of  the  internal  oblique^"  and 
transversalis  muscles. 

Inferiorly.  the  union  of  the  transversalis  fascia  ^^  with  Pou- 
part's  and  Gimbernat's  ligament*'. 

What  is  Poupart's  ligament^? 

The  infolded,  thickened  margin  of  the  aponeurosis  of  the  ex- 
ternal oblique,  extending  from  the  anterior  superior  iliac  spine ^ 
to  the  spine  of  the  pubes,  from  which  it  is  reflected  a  short 
distance  along  the  pectineal  line,  forming  Gimhernat' s  ligament ; 
an  oblique  band  of  fascia  or  tendinous  fibers  arises  from  the 
external  oblique  aponeurosis  of  one  side  to  be  inserted  into  the 
pubic  crest  and  the  pectineal  line  of  the  opposite  side,  passing 
inward  beneath  the  spermatic  cord  behind  the  inner  pillar,  in 
front  of  the  conjoined  tendon  ;  it  is  called  the  triangular  fascia 
of  the  abdomen ;  the  lower  part  of  Poupart's  ligament  forms 
the  external  pillar  of  the  external  abdominal  ring*. 

Describe  the  relations  of  the  epigastric  artery  and  the  inter- 
nal abdominal  ring. 
It  passes  between  the  transversalis  fascia  and  the  peritoneum 
along  the  lower  inner  margin  of  the  internal  ring  beneath  the 
spermatic  cord. 

What  is  the  cremasteric  fascia? 

A  series  of  muscular  loops  connected  by  areolar  tissue  in- 
vesting the  spermatic  cord,  supposed  to  have  been  derived  from 
the  internal  oblique  muscle  during  the  descent  of  the  testicle, 
and,  of  course,  absent  in  the  female. 


FEMORAL  HERNIA.  383 

What  is  Hesselbach's  triangle  ? 

A  triangular  space  at  the  lower  part  of  tlie  inner  surface  of 
the  abdominal  wall,  bounded  externally  by  the  epigastric  artery, 
and  a  fold  of  the  peritoneum  covering  it,  the  j}/ica  epigastricd; 
internally  by  the  margin  of  the  rectus  muscle,  and  below  by 
Poupart's  ligament ;  the  conjoined  tendon  stretches  across  the 
inner  two-thirds  of  this  space. 

What  is  an  external  or  oblique  inguinal  hernia? 

A  protrusion  of  an  abdominal  viscus,  usually  of  the  bowel, 
omentum,  or  both,  following  the  course  of  the  spermatic  cord 
in  the  inguinal  canal  through  both  the  internal  and  external 
rings  (icheii  complete),  the  neck  of  the  sac  being  to  the  outer 
side  of  the  epigastric  artery. 

What  are  the  coverings  of  an  oblique  inguinal  hernia? 

Skin;  superjickd  fascia ;  intercolainnar  fascia;  cremasteric 
fascia ;  infundihuliform  fascia^  modified  transversalis  fascia  ; 
subserous  cellular  tissue;  and  peritoneum  forming  the  sac. 

Where  is  the  seat  of  stricture  most  apt  to  be? 

(1)  At  the  internal  ring,  (2)  the  inguinal  canal  by  fibers  of 
the  internal  oblique  or  transversalis  muscles,  (3)  at  the  exter- 
nal ring,  provided  it  is  not  at  the  thickened  neck  of  the  sac, 
the  most  usual  site  in  old  hernise. 

What  is  an  internal  or  direct  inguinal  hernia? 

One  wliere  the  protrusion  passes  through  some  part  of  Hes- 
selbach's triangle,  passing  directly  through  the  external  ab- 
dominal ring,  the  neck  of  the  sac  being  internal  to  the  epi- 
gastric vessels. 

What  coverings  has  a  direct  hernia? 

The  same  as  an  oblique,  except  that  the  transversalis  fascia 
takes  the  place  of  the  iufandihuliform  fascin ,  and  the  con  joined 
tendon  is  substituted  for  the  cremasteric  fascia ;  the  fibers  of 
the  tendon  may  be  forced  apart  or  distended  as  an  investment. 

FEMORAL    HERNIA. 

Describe  the  femoral  or  crural  canal  (Fig.  150). 

ft  lies  beneath  Foupart's  ligament",  to  the  inner  side  of  the 
femoral  vein'^,  extending  from  the  femoral  ring  above  to  the 


384  ESSENTIALS  OF  HUMAN   ANATOMY. 

S((j}Jt('itoi(s  opcniuy^'  below  ;  it  is  about  half  an  inch  long,  closed 
above  by  the  sej)tnm  cj-ura/c,  formed  of*  condensed  areolar  tissue, 
and  below  by  the  ci'tbri/orm  fascia,  derived  from  the  deep  layer 
of  the  superficial  fascia,  or  from  the  fascia  lata,  covering  the 
saphenous  opening. 

The  femoral  or  crural  ring  is  an  oval  space  between  the 
femoral  vein  and  (rim])eriiat's  ligament,  three-fifths  to  one  inch 
in  diameter,  larger  in  the  female  than  in  the  male,  situated  be- 
low and  internal  to  the  internal  abdominal  ring  ;  it  is  closed 
by  the  septum  crurale  and  a  lymphatic  gland  ;  the 

Saplicnous  opciiing^\  fossa  ovalis,  is  an  ovoidal  opening  one 
and  a  half  inches  long  by  half  an  inch  wide,  below  the  inner 
portion  of  Poupart's  ligament'^,  formed  by  the  pubic  portion ^^ 
of  the  fascia  lata  passing  behind  the  femoral  vessels,  while  contin- 
uous with  it  by  the  inferior  cornn  is  a  stroug  falciform  process  of 
Barns  ^^,  the  iliac  portion  of  the  fascia  lata,  ])assing  in  front  of  the 
vessels,  its  narrow  pubic  portion  blending  with  the  attachment 
of  Poupart's  and  Gimbernat's  ligaments  ;  this  is  called  Ileifs 
ligament^^  or  the  superior  cornu ;  the  opening  is  covered  in  by 
the  cribriform  fascia. 

Bound  the  crural  canal. 

Anteriorh/  lie  the  transversalis  fascia^\  Poupart's  ligament^, 
and  the  falciform  process  of  the  fascia  lata^'' ; 

Posteriori}/^  iliac  fascia,  covering  the  pubic  portion  of  the 
fascia  lata ; 

External  It/,  the  fibrous  septum  separating  it  from  the  femoral 
vein  ; 

Internall//,  the  junction  of  the  processes  of  the  transversalis 
and  iliac  fasciae  fonning  the  femoral  sheath  lying  against  the 
outer  concave  edge  of  Gimbernat's  ligament. 

Describe  the  position  of  parts  around  the  ring. 

The  spermatic  cord  in  the  male,  the  round  ligament  in  the 
female,  lie  just  above  the  anterior  margin  ;  the 

Femond  vein^^  lies  upon  its  outer  side  ;  the 

Epigastric  artery  crosses  the  upper  outer  angle  of  the  ring; 
the 

Obturator  artery  once  in  three  and  a  half  cases  arises  in 
common  with  the  epigastric,  when  it  may  closely  skirt  around 
the  upper  and  inner  margins  of  the  ring. 


THE  PERINEUM   AND   ISCHIO-RECTAL   REGIONS.   385 

Describe  the  septum  crurale. 

It  is  a  layer  of  condensed  cellular  tissue  upon  which  lies  a 
small  lymphatic  gland,  closing  the  femoral  ring. 

What  is  the  crural  sheath  ? 

It  is  a  continuation  downward  of  the  fascia  transversalis  in 
front,  and  of  the  iliac  fascia  behind  the  femoral  vessels  forming 
their  sheath,  divided  by  two  septa  into  three  compartments  for 
the  femoral  artery  externally,  the  femoral  vein  next,  and  leav- 
ing a  third  internally,  the  femoral  oanal,  or  opportunity  for  ic. 

Describe  the  deep  crural  arch. 

When  present  it  is  a  band  of  fibers  derived  from  the  trans- 
versalis fascia,  crossing  the  front  of  and  adherent  to  the  crural 
sheath,  passing  from  the  center  of  Poupart's  ligament,  the 
superficial  crural  arch,  to  the  pectineal  line  behind  the  con- 
joined tendon. 

Where  is  the  seat  of  stricture  most  apt  to  be  ? 

At  (1)  the  junction  of  Hey's  and  Gimbernat's  ligaments, 
(2)  the  margin  of  the  saphenous  opening,  (3)  the  neck  of  the 
hernial  sac. 

What  are  the  coverings  of  a  femoral  hernia? 

They  are  skin,  siq^er/icial  fascia,  cribriform  fascia,  crural 
sheath,  sejytum  crurale,  subserous  areolar  tissue,  and  peritoneum 
forming  the  sac. 

THE   PERINEUM   AND   ISCHIO=RECTAL   REGIONS. 

Perineum  (Fig.  151)  includes  the  outlet  of  the  pelvis  from 
the  apex  of  the  subpubic  arch  to  the  tip  of  the  coccyx,  between 
the  ischial  tuberosities ;  breadth,  three  and  a  half  inches 
(9  cm.)  ;  length,  four  inches  (10  cm.).  A  transverse  line  just 
in  front  of  the  anus  marks  an  anterior  urethral  part,  true  per- 
iueum,  and  a  posterior  anal  jxirt,  the  ischio-rectal  region. 

Ischio-rectal  fossa^,  of  a  triangular  shape,  between  the  end 
of  the  rectum"  and  the  tuberosity  of  the  ischium"  on  each  side; 
its  base  corresponds  to  the  skin,  and  apex  to  the  point  of 
division  of  the  obturator  fascia  and  the  origin  of  the  anal 
fascia  ;  its  base  is  about  one  inch  broad,  its  depth  two  inches, 
being    deepest    behind,    and    is    bounded    internally,    by    the 

25 


386  ESSENTIALS  OF  HUMAN   ANATOMY. 

sphincter  ani^.  levator  ani^,  and  coccygeus®  muscles  ;  externally^ 
by  the  tuberosity  of  the  ischium"  and  obturator  fascia ;  in 
froiit^  by  the  line  of  junction  of  the  superficial  and  deep 
perineal  fasciae;  and  hr/u'nd,  by  the  margin  of  the  gluteus 
maximus  muscle'^  and  the  great  sacro-sciatic  ligament. 

Internal  pudic  ve.ssrh  and  nerve  run  about  one  and  a  half 
inches  above  the  margin  of  the  ischiatic  tuberosity,  in  Alcock's 
canal. 

Inferior  hemorrhoichd  vessels,  occasionally  large  enough  to 
give  trouble  after  lithotomy,  traverse  the  center  of  each  fossa. 

What  is  the  perineum  ? 

It  is  the  anterior  portion  of  the  pelvic  outlet,  in  front  of  the 
ischio-rectal  region  ;  it  is  of  a  triangular  form,  bounded,  deeply, 
by  the  rami  of  the  pubes  and  ischia,  forming,  superiorly,  the 
pubic  arch,  and  behind,  by  a  line  drawn  between  the  ischiatic 
tuberosities ;  lateral  boundaries  measure  three  to  three  and  a 
half  inches.  The  central  point  of  the  perineum  is  one  inch, 
membranous  urethra  one  and  a  half  inches,  in  front  of  the 
anus. 

Describe  the  muscles  of  the  perineum. 

External  sphincter  ani "^ :  origin^  the  tip  of  the  coccyx''  by  a 
tendinous  band  and  superficial  fascia  ;  insertion,  the  tendinous 
center  of  the  perineum'^;  action,  closes  the  anus  ;  nerve,  the  fourth 
sacral  and  the  inferior  hemorrhoidal  of  the  pudic. 

Internal  sphincter  ani :  consists  of  an  aggregation  of  the 
involuntary  circular  fibers  of  the  intestine,  forming  a  muscular 
ring  around  the  anal  canal  two  lines  thick  and  one  inch  broad. 

Sphincter  tertius  (p.  276)  :  a  transver.se  fold  extending  into 
the  rectum  on  the  right  .side  three  inches  above  the  anus. 

Accelerator  urinse^  bulho-cavernosus :  it  has  symmetrical  halves 
with  a  median  raphe  ;  origin,  central  tendon  of  the  perineum'-^  and 
the  median  raphe  in  front ;  insertion,  fibers  spread  over  the 
front  of  the  triangular  ligament,  encircle  the  bulb  and  corpus 
spongiosum,  spread  over  the  sides  of  the  corpora  cavernosa,  to 
which  they  are  partly  attached  and  partly  terminate  in  a  tend- 
inous expansion  covering  the  dorsal  vessels  of  the  penis  ;  action, 
empties  the  urethra  after  the  bladder  ceases  to  contract,  per- 
haps aids  in  the  erection  of  the  penis ;  nerve,  perineal  branch 
of  the  pudic, 


THE  PERINEUM  AND  ISCHIO-RECTAL   REGIONS.   387 

Erector  penis'*,  ischio-cavernosus :  origin^  inner  surface  of  the 
tuberosity  of  the  ischium,  and  the  adjacent  portion  of  its 
ramus  {erector  ditoridis  in  the  female  arises  from  the  ischial 
tuberosity  ;  utserted  on  the  side  of  the  crus  clitoridis)  ;  inser- 
tion^ by  an  aponeurosis  covering  the  crus  penis  into  the  outer 


Fig.  151.— The  muscles  of  the  perineum  (Leidy). 


side  and  the  under  surface  of  that  body ;  action^  maintains 
erection  ;  nerve,  perineal  of  the  pudic. 

Transversus  perinei^ :  origin,  inner  front  side  of  the  tuberosity 
of  the  ischium  ;  insertion,  tendinous  center  of  the  perineum 
meeting  its  fellow,  external  sphincter,  and  accelerator  urinae ; 
action,  steadies  the  perineal  center  ;  nerve,  perineal  of  the  pudic. 

Levator  anr :  origin,  posterior  surface  of  the  body  of  the 
OS  pubis,  spine  of  the  ischium,  from  the  "  white  line,"  which 
is  the  angle  of  division  between  the  obturator  and  recto- 
vesical layers  of  the  pelvic  fascia;  insertion,  sides  of  the  apex 
of  the  coccyx**,  opposite  muscle  by  a  median  fibrous  raphe, 
extending  from  the  coccyx  to  the  anal  margin,  the  side  of 
the  rectum  (or  vagina)  blending  with  the  s])hinctcr  muscles, 
and  the  side  of  the  prostate  gland,  uniting  beneath  it  with  the 
opposite  muscle  mingling  with  the  external  sphincter  and  trans- 


388  ESSENTIALS  OF  HUMAN   ANATOMY. 

versus  perinei  muscles  at  the  perineal  center ;  action,  supports 
tlie  rectum,  vagina,  and  pelvic  viscera,  and  with  its  fellow  helps 
to  form  the  floor  of  the  pelvis,  a  muscle  of  forced  expiration ; 
nerves,  perineal  of  the  ])udic  and  the  fourth  sacral. 

Compressor  or  constrictor  uretlirse  :  oriyln.  aponeurotic,  from 
the  ischio-pubic  rami  on  each  side,  from  layers  of  the  triangu- 
lar ligament;  insertion,  each  muscle  divides,  surrounding  the 
urethra  from  the  prostate  gland  to  the  bulb  of  the  urethra, 
uniting  with  the  opposite  muscle  above  and  below  this  tube 
by  a  tendinous  raphe:  action,  shut-off  muscle;  nerves,  dorsal 
nerves  of  the  penis  from  the  pudic. 

Coccygeus^ :  origin,  from  the  spine  of  the  ischium,  lesser  sacro- 
sciatic  ligament,  or  obturator  fascia  ;  insertion,  into  the  margin 
of  the  coccj'x  and  the  side  of  the  lowest  segment  of  the  sac- 
rum ;  action,  raises  the  coccyx;  completes  the  pelvic  floor; 
iierif.  anterior  branch   of  the  fourth  and  fifth  sacral. 

Sphincter  vaginae  surrounds  the  vaginal  orifice,  and  is  homolo- 
gous with  the  accelerator  urinaB  in  the  male  ;  origin,  central  ten- 
don of  the  perineum  ;  insertion,  corpora  cavernosa  of  the  clitoris. 

Erector  clitoridis :  it  replaces  the  erector  penis  muscle. 

Describe  the  perineal  fasciae. 

The  siijx  rjiciaJ  layer  ejf  the  superficial  fascia  is  thick,  loose, 
loaded  with  fat.  and  continuous  with  the  fasciae  of  the  ischio- 
rectal and  crural  regions  ;  it  has  no  bony  attachments  ;  the 

Deep  layer  of  the  superficial  fascia,  sup>erficial  perineal  fascia, 
Colles  fascia,  are  three  names  for  an  aponeurotic  layer,  con- 
tinuous in  front  with  the  dartos  of  the  scrotum,  is  firmly  at- 
tached to  the  margins  of  the  ischio-pubic  rami,  external  to  the 
crura  of  the  penis  as  far  back  as  the  ischial  tuberosities,  and 
passes  behind  the  transversus  perinei  muscles  to  become  the 
anterior  layer  of  the  deep  perineal  fascia. 

The  anterior  layer  of  the  deep  perineal  fascia  is  attached 
above  and  laterally  to  the  pubic  arch,  subpubic  ligament  and 
rami  of  the  ischium  and  pubes  beneath  the  crura  of  the  penis, 
forming  a  dense  membranous  lamina,  extending  and  attached 
to  the  tendinous  perineal  center  becoming  continuous  with  the 
deep  layer  of  the  superficial  fascia  behind  the  transverse  peri- 
neal muscles ;  it  embraces  the  anterior  extremity  of  the  mem- 
branous urethra,  which  passes  through  it  one  inch  below  the 
symphysis  pubis,  and  is  continued  forward  upon  it. 


THE  PERINEUM  AND  ISCHIO-RECTAL  REGIONS.  389 

The  posterior  layer  of  the  deep  perineal  fascia  is  attached  like 
the  preceding,  but  more  posteriorly,  embraces  the  back  of  the 
membranous  urethra,  and  is  continued  backward  over  the  outer 
surface  of  the  prostate  gland,  the  two  layers  forming  the  tri- 
angular ligament ;  the  portion  of  the  urethra  embraced  between 
these  layers  is  the  membranous  urethra. 

The  p>^^vic  fascia  shows  a  white  line  passing  from  the  lower 
part  of  the  symphysis  pubis  to  the  spine  of  the  ischium  ;  this 
marks  the  line  of  division  into  two  layers,  obturator  and  recto- 
vesical fasciie.  The  former  covers  the  lower  part  of  the  obtu- 
rator internus,  gives  off  anal  fascia  to  the  under  surface  of  the 
levator  ani ;  passing  across  the  subpubic  arch  it  forms  the  pos- 
terior layer  of  the  triangular  ligament. 

The  recto-vesical  fascia,  or  visceral  layer  of  the  pelric  fascia., 
descends  into  the  pelvis  upon  the  upper  surface  of  the  levator 
ani  muscle,  investing  the  prostate,  bladder,  and  rectum. 

Describe  Buck's  or  Colics'  fascia. 

It  is  a  moderately  dense  fascia  investing  the  penis  as  far  as 
the  glans,  being  a  prolongation  downward  of  the  deep  layer  of 
the  superficial  abdominal  fascia,  forming  the  dartos  of  the 
scrotum  ;  it  directs  the  urine  forward  into  the  scrotum,  penis, 
and  upon  the  abdomen  in  rupture  of  the  urethra. 

What  layers  of  fascia  form  the  triangular  ligament  ? 

The  superficial  and  deep  layers  of  the  (hep  perineal  fascia^ 
or  the  anterior  and  posterior  layers  of  the  triangular  ligament 
(body  horizontal),  or  the  inferior  and  superior  frianguhir  liga- 
ments (body  erect)  ;  there  are  three  names  for  each  layer. 

What  structures  lie  between  the  layers? 

Memhranons  urethra,  Cowpers  glands  and  ducts, 

Compressor  vrethrse.  muscle,        Internal  pud ic  vessels, 
Subpubic  ligament,  Pudic  nerves, 

Dorsid  vessels  of  the  penis.         Arteries  and  nerves  of  bulb, 
Dorsal  nerves  of  the  jyejiis,  Venous  plexus. 

What  structures  are  exposed  by  the  removal  of  the  deep 
layer  of  the  superficial  fascia? 
The  erector  penis  muscles  covering  the  crura  of  the  j)enis. 
The  accelerator  urinae  muscle  covering  the  corpus  sjiongiosiim 

and  bulb, 


390  ESSENTIALS  OF  HUMAN  ANATOMY. 

Transversns  pcrlnci  mitscles, 
Transverse  perineal  arteries^ 
Superficial  perineal  vessels. 

What  parts  are  divided  in  lateral  lithotomy  ? 
Skin, 

Superficial  and  Colics''  fascia, 
Inferior  hemorrhoidal  vessels  and  nerves, 
Posterior  fibers  of  the  accelerator  urinse  muscle, 
Transversus  perinei  muscle  and  vessels, 
Stiperficud  perineal  vessels  and  nerves. 
Triangular  ligament,  two  layers. 
Anterior  filters  of  the  levator  ani. 
Part  of  the  compressor  urethrse. 
Membranous  and  prostatic  portions  of  the  urethra, 
Lateral  lobe  of  the  prostate  gland. 

What  structures  must  be  avoided  in  this  operation? 

In  front,  the  bulb  and  its  artery. 

Externally,  the  internal  pudic  vessels  and  nerve. 

Toiuard  the  median  line  and  posteriorly,  the  rectum  or  neck 
of  the  bladder,  the  entire  division  of  the  lateral  lobe  of  the 
prostate,  venous  plexus,  or  pelvic  fascia. 

Briefly  describe  the  special  points  of  interest  connected  with 
the  female  perineum. 

The  perineal  body  is  the  point  of  junction  of  all  the  muscu- 
lar and  aponeurotic  structures  of  the  perineum,  forming  a 
pyramidal  mass  of  tissue  extending  for  some  distance  up  be- 
tween the  rectum  and  vagina,  upon  the  integrity  of  which  de- 
pends the  proper  support  aiforded  to  the  pelvic  viscera  by  the 
fioor  of  the  pelvis. 

The  length  of  the  female  perineum  is  only  about  one  inch, 
extending  from  the  posterior  commissure  to  the  verge  of  the 
anus;  the  accelerator  urinpe  muscle  is  replaced  by  the  sphincter 
vaginse  encircling  the  vaginal  outlet ;  the  triangular  ligament, 
formed  essentially  as  in  the  male,  and  perforated  by  the  ure- 
thra and  vagina,  is  much  smaller  and  weaker. 


INDEX. 


Abdomen,  289 

muscles  of,  156 

openings  in,  289 

regions  of,  290 
Abdominal  aorta,  201 

surgical  anatomy,  212 

regions,  290 

ring,  external,  381 
internal,  381 

viscera,  289 
Abflucens  nerve,  246 
Abductor  hallucis,  179 

minimi  digiti,  169,  180 

pollicis,  168 
Accelerator  urinse,  386 
Acetabulum,  83 

Aci-omio-clavicular  articulation,  126 
Acromion  process,  92 
Acromio-thoracic  artery,  197 
Adductor  brevis,  172 

longus,  172 

magnus,  172 

obliquus  hallucis,  180 
pollicis,  168 

transversus  liallucis,  181 
pollicis,  168 

tubercle  of  femur,  109 
Agminated  glands,  274 
Alar  thoracic  artery,  198 
Alim(!ntarj'  canal,  subdivisions  of, 

260 
Alveolar  artery,  344 

process,  46 
Alv(!oli  of  lungs,  307 
Ainpulla  of  labyrinth,  373 
Ampullsr'  of  maiinna,  339 
Amygdala  of  ccrchcllum,  237 
Anal  canal,  276 
Anastomotica  magna,  198,  208 
Anatomical  neck  of  humerus,  95 


Anatomy,  definition  of,  17 

descriptive,  17 

regional,  17 

surgical,  17 
Anconeus,  166 
Angle  of  jaw,  56 

subscapular,  91 
Angular  gyrus,  227 

processes  of  frontal  bone,  23 
Anlile-joint,  137 
Annular  ligament,  anterior,  167 
of  foot,  178 
posterior,  167 
of  stapes,  369 
of  wrist,  130 
Annulus  ovalis,  183 
Anterior  fossa  of  skull,  58 
j  Antihelix,  363 
j  Antitragicus,  364 
j  Antitragus,  363 
Antrum  of  Highmore,  46 
Anus,  276 
Anvil,  368 
Aorta,  188 

abdominal,  201 

relations  of,  in  thdrax,  189 

thoracic,  200 
Aortic  plexus,  259 

valve,  182 
Apex  of  lung,  303 
Ai)oneuroses,  141 
Apoi>hysis,  21 
Api)endages  of  eye,  359 
Appendices  ejiiploicee,  276 
Appendix  aiiricula',  183 

vermiformis,  275 
Aqujeductus  cochleip.  38,  375 

vestihuli,  38,  60,  373 
Aqueous  cliamhers,  354 

humor,  354 


392 


INDEX. 


Aiacbnoifl,  223,  240 
Arbor  vitte  uterina,  335 
Arch,  supra-orbital,  23 
Area  cribrosa,  379 
Areola  of  nii)i)le,  339 
Arm,  bones  of,  95 

nuiscles  of,  IGl 
Arnold's  ganglion,  244 
Arrectores  pi  lorn  ni,  342 
Arteria  centralis  retinse,  357 
Arteriae  proprijc  renales,  315 

receptaculi,  194 

rectse,  315 
Arteries,  186 

of  ankle-joint,  137 

of  auricle,  364 

of  bladder,  321 

cerebral,  194 

of  choroid,  349 

coronary,  189 

of  elbow-joint,  129 

of  esophagus,  270 

of  Eustachian  tube,  372 

of  eyeball,  357 

of  eyelids,  360 

helicine,  326 

of  hip-joint,  133 

interlobular,  315 

of  iris,  351 

of  kidney,  315 

of  knee-joint,  136 

of  labyrinth.  380 

of  larynx,  300 

of  liver,  282 

of  lungs,  307 

of  mammfe,  340 

of  ruembrana  tvmpaui,  366 

of  nose,  343,  344 

of  ovaries,  339 

of  pancreas.  284 

of  penis,  .326 

of  pharynx,  269 

of  retina,  3.52 

of  sclerotic,  .347 

of  shoulder-joint,  128 

of  stomach,  272 

structure  of,  187 

surgical  anatomv  of,  211 

of  testicle,  329 

of  trachea,  .303 

of  tympanum,  .369 

of  uterus,  .3.36 

of  wrist-joint,  130 
Artery,  acromio-thoracic,  197 


Artery,  alar  thoracic,  198 
alveolar,  344 
auricular,  posterior,  192 
ax  i  liar  V,  197 
basilar,'  196 
brachial,  198 
bronchial,  200 
carotid,  common,  190 

internal,  193 
celiac  axis,  201 
ciliary,  .357 

circumflex,  posterior,  198 
coronary,  of  stomach,  201 
cremasteric.  3.30 
dorsalis  pedis,  210 
epigastric,  deep,  205 

circumflex,  206 

superficial,  208 

superior,  196 
esophageal,  200 
facial,  192 
femoral,  206 
gastric,  201 
gluteal,  205 
hepatic,  202,  281 
hypogastric,  204 
iliac,  204 

common,  203 

external,  205 

internal,  203 

superficial  circumflex,  208 
ilio-lumbar,  205 
infraorbital,  .3.57 
innominate,  189 
intercostal,  201 

superior,  196 
lacrimal,  357 
lingual,  191 
lumbar,  203 

mammary,  internal,  196 
maxillary,  internal,  192 
medullary,  19,  198 
mesenteric,  inferior,  202 

superior,  202 
metatarsal,  210 
musculo-phrenic,  196 
obturator.  204 
occipital,  192 
ophthalmic,  194,  357 
ovarian,  203,  336 
palpebral,  3.57 
pericardial,  200 
peroneal,  210 
pharyngeal,  ascending,  192 


INDEX. 


393 


Artery,  phrenic,  inferior,  202 

plantar,  external,  211 
internal,  211 

popliteal,  208 

profunda,  inferior,  198 
superior,  198 

pudic,  internal,  204 

pulmonary,  187 

radial,  199 

renal,  202,  315 

sacral,  lateral,  205 
middle,  203 

sciatic,  204 

spermatic,  203,  329 

splenic,  202,  286 

subclavian,  195 

subcostal,  201 

subscapular,  198 

supraorbital,  357 

suprarenal,  inferior,  203 
middle,  202 

suprascapular.  196 

tarsal,  210 

temporal,  superficial,  192 

thoracic,  long,  198 
superior,  197 

thyroid,  196 

superior,  191 

tibial,  anterior,  209 
posterior,  210 

tympanic,  194,  370 

ulnar,  199 

uterine,  204,  336 

vertebral,  196 

vesical,  204 
Arthrodia,  118 
Articular  cavities  of  bone,  21 

nerve  of  internal  po])liteal,  254 

processes  of  vertebra,  71 
Articulations,  117 

acrornio-clavicular,  126 

astragalo-navicular,  138 

atlanto-axial,  120 

carpal,  130 

carpo-metacarpal,  131 

chondro-sternal,  123 

costo-central,  122 

costo-transvcrse,  123 

costo- ventral,  122 

ijitcrfboridral,  124 

int(  rplialangcal,  132.  139 

of  btwcr  extremity,  1.32 

metacari»o-pbaIan;i('aI,  132 

mctatarsd-plialanfrcal,  1.39 


Articulations,  occipito-atlautal,  119 

radio-ulnar,  129 

sacro-coccygeal,  125 

sacro-iliac,  124 

sacro-vertebral,  124 

sterno-clavicular,  126 

tarsal.  138 

tarso-metatarsal,  139 

temporo-maxillary,  122 

tibio-fibular,  1.36  " 

vertebral,  119 
Aryteno-epiglottideus  inferior,  300 

superior,  300 
Arytenoid  cartilages,  296 
Arytenoideus,  300 
Ascending  colon,  275 

frontal  convolution,  227 

parietal  convolution,  227 
Astragalus,  113 

Atlanto-axial  articulation,  120 
Atlas.  72 

Attolens  aurem,  142 
Attrahens  aurem,  142 
Auditory  canal,  external,  364 

nerve,  246,  379 
Auricle,  363 

arteries  of,  364 

left,  184 

right,  183 
Auricular  artery,  posterior,  192 

fissure,  39  " 

surface  of  sacrum,  76 
Auriculo-ventricular  groove, 182, 183 

orifice,  183 
Axillary  arterj-,  197 

surgical  anatomy,  212 

vein,  215 
Axis,  72,  73 
Axis  cylinder,  222 
Azygos  uvulae,  148 

veins,  217 

Back,  muscles  of,  150 
Bartholin,  duct  of,  264 

glands  of,  333 
Basal  ganglia,  229 
Ba.silar  arterv,  196 

cells,  378 

groove,  30 

process  of  occipital,  29 
Basi-occipitals,  27 
Basi-sphenoidal  suture,  .57 
Baubin,  valve  of,  273 
Bic(!ps,  174 


394 


INDEX. 


Biceps,  flexor  cubiti,  162 
Bicipital  groove,  95 
Bicuspid  teeth,  261 
Bladder,  318 

ligaments  of,  319 

nerve-supply  of,  321 

structure  of,  320 

vessels  of,  321 
Blind  spot,  352 
Body,  ciliary,  349 

perineal,  390 

pituitary,  229 

restiform,  235 

of  vertebra,  70 

vitreous,  354 
Bone,  astragalus,  113 

atlas,  72 

axis,  73 

chemical  composition  of,  17 

clavicle,  89 

coccyx,  77 

cuboid,  114 

cuneiform,  103,  114 

ethmoid,  40 

femur,  106 

fibula,  112 

frontal,  22 

humerus,  95 

hyoid,  76 

ilium,  85 

of  the  Incas,  27 

incus,  368 

innominate,  83 

ischium,  86 

lacrimal,  48 

malar,  49 

malleus,  368 

maxillary,  inferior,  54 
superior,  43 

microscopic  structure  of,  18 

nasal,  43 

navicular,  114 

occipital,  27 

OS  calcis.  113 

OS  maguum,  104 

palate,  50 

parietal,  25 

patella,  109 

pelvis,  88 

phalanges  of  foot,  117 
of  hand,  106 

pisiform,  104 

pubes,  87 

radius,  100 


Bone,  sacrum,  74 

scaphoid,  102 

scapula,  91 

semilunar,  102 

sphenoid.  31 

stapes,  368 

sternum,  80 

temporal,  35 

tibia,  110 

trapezium,  104 

turbinated,  42 
inferior,  52 

ulna,  97 

unciform,  104 

vomer,  53 
Bones  of  arm,  95 

classification  of,  20 

of  foot,  113 

of  forearm,  97 

of  hand,  102 

of  head,  22 

of  lower  extremity,  106 

of  trunk,  69 

of  upper  extremity,  89 

long,  20 

number  of,  20 

pelvic,  83 

sesamoid,  20 

Wormian,  20 
Bowman's  capsule,  313 

membrane,  348 
Brachial  artery,  198 

surgical  anatomy,  212 

plexus,  249 
Brachial  is  anticus.  163 
Brachio-radialis,  165 
Brain,  224 

convolutions  of,  226 

fissures  of,  225 

ventricles  of,  231 

weight  of,  224 
Brim  of  pelvis,  88 
Broad  ligament  of  liver,  277,  278 
pulmonary.  308 
of  uterus,  335 
Bronchi,  302 
Bronchial  artery,  200 
Bronchioles,  307 
Bruch,  membrane  of,  349 
Brunner's  glands,  274 
Buccinator,  144 
Buck's  fascia,  .389 
Bulb  of  corpus  callosum,  325 

of  corpus  spongiosum,  325 


INDEX. 


395 


Bulbi  vestibuli,  333 
Bulbs,  olfactory,  232 
Burns,  falciform  process  of,  384 
Bursa,  pharyngeal,  268 
subcrural,  134 

Calamus  scriptorius,  234 
Calcarine  fissure,  226 
Calices  of  kidney,  313 
Calloso-marginal  fissure,  226 
Canal,  alimentary,  260 
anal,  276 

for  Arnold's  nerve,  61 
auditory,  external,  364 
carotid,  38 
central,  of  cord,  241 
crural,  383 
dental,  44,  56 
femoral,  383 
Haversian,  18 
of  Huguier,  36,  367 
hyaloid,  354 
infraorbital,  45 
inguinal,  381 
for  Jacobson's  nerve,  01 
malar,  64 

medullarv,  of  humerus,  95 
of  neck,  336 
palatine,  52 
of  Petit,  355 
portal,  282 
sacral,  76 
of  Sclilemm,  350 
semicirciihir,  373 
spiral,  374 
of  Stilling,  354 
for  tensor  tvmpani  muscle, 
of  tibia,  110 
Vidian,  34 
of  Wirsung,  284 
Canal iculi  of  bone,  18 

lacrimal,  361 
Canalis  centralis  modioli,  374 
cochlea',  377 
hypoglossi,  30 
rcuniens,  377 
(Cancellous  tissue  of  bone,  18 
Canine  teeth,  261 
Can  Hi  us  of  eye,  359 
Capillaries.  187 
Capsular  ligament.  119 
of  hip,  1.32 
of  ossicles,  369 
Capsule  «»r  I'.owman,  313 


61 


Capsule  of  Glisson,  276,  279,  281 
of  lens,  3.54 
of  Tenon,  345 
Capsules,  suprarenal,  288 
Caput  coli,  274 

gallinaginis,  322 
Cardia  of  stomach,  270 
Cardiac  incisure,  305 
nerve,  inferior,  257 

superior,  256 
plexus,  great,  258 

superficial,  2.59 
veins,  220 
Carotid  artery,  common,  190 

surgical  anatomy,  211 
internal,  193 
canal,  38 
plexus,  2.57 
Carpal  articulations,  130 

bones,  102 
Carpo-metacarpal  articulations,  131 
Cartilage  arytenoid,  296 
cricoid,  295 
thyroid,  295 
Cartilages,  costal,  83 
cuneiform,  297 
of  larynx,  295 
of  Santorini,  297 
tarsal,  360 
of  Wrisberg,  297 
Caruncula  lacrimalis.  .361 
Carunoulfe  myrtiformes,  .333 
Cauda  ec^uina,  2.56 
Caudate  nucleus.  2.30 
Cavernous  groove,  32 

plexus,  2.57 
Cavities  of  bones,  21,  22 

orbital,  61 
Cavity,  sigmoid,  99,  100 
Cavum  Meckelii,  244 
Cecum,  274 
Celiac  axis,  201 
Cells  of  Dieters,  379 

gustatory,  343 
Cement  of  tooth,  261 
Center  of  ossification,  20 
Central  loJ>e,  22() 
Cerebellum.  23fi 

arrangement  of  grav  matter  of, 

237 
lobes  of,  236 
peduncles  of,  235,  237 
sulci  of.  23(» 
Cerebral  arteries,  194 


396 


INDEX. 


Cerebral  fissures,  225 

fossa,  ]ioslerior,  60 

Ibssai,  ry6 

lobes,  225 
Cerebrospinal  fluid,  240 
Cervical  ganglia,  25G,  257 

plexus,  248 
Cervicalis  ascendens,  153 
Cervix  uteri,  334 
Chambers  of  eye,  354 
Check  ligament,  121 
Chondrigen,  17 

Chondro-sternal  articulations,  123 
Chorda  tympani,  2(i(),  370 
Chorda;  tendine?e,  184 
Choriocapillaris,  349 
Choroid,  348 

plexus,  232 
Cilia.  360 
Ciliary  arteries,  357 

body,  349 

ganglion,  244 

muscle,  349 

nerve,  358 

processes,  349 
Circle  of  Willis,  194 
Circulus  arteriosus,  349 

venosus,  340 
Circumferential  lamellfe,  19 
Circumflex  artery,  anterior,  198 
posterior,  198 

nerve,  250 
Circum vallate  papillae,  266 
Clavicle,  89 

development  of,  91 

muscular  attachmeuts  of,  91 
Clinoid  processes,  32 
anterior,  34 
Clitoris,  332 
Clivis,  237 
Coccygeal  ganglion,  256 

nerves,  256 
Coccygeus,  388 
Coccyx,  77 
Cochlea,  374 

membranous  canal  of,  377 
Cochlear  nerve,  379,  380 
Collateral  fissure,  226 
Colles'  fascia,  388,  389 
Colliculus  nervi  optici,  352 
Colon,  274 

ascending,  275 

descending,  275 

transverse,  275 


Columnfc  carncpe,  184 
(Jolumns  of  liertin,  313 

of  spinal  cord,  240 

of  vagina,  334 
Commissures,  cerebral,  230 
Communicans  fibularis,  254 

peronei,  254,  255 
Comjjact  tissue  of  bone,  18 
CompU'XUS,  154 
Compressor  narium  minor,  144 

nasi,  144 

urethra,  388 
Concentric  lamella^,  18 
Concha,  363 

Condylar  foramen,  anterior,  30 
l)osterior,  29 

fossa,  posterior,  29 
Condvles,  21 

of  femur,  108 
Condyloid  foramen,  anterior,  61 
posterior,  61 

process,  54 
Con  e-gran  u  1  es,  353 
Cone-foot,  353 
Cone  of  ligbt,  365 
Coni  vasculosi,  328 
Conjoined  tendon,  156 
Conjunctiva,  360 
Conoid  tubercle,  90 
Constrictor  muscles  of  pharynx,  268 

urcthrfe,  388 
Con  us  arteriosus,  184 

medullaris,  240 
Convolutions  of  brain,  226 
Coraco-bracbialis,  162 
C'oracoid  process  of  scapula,  93 
Cornea,  347,  348 
Cornicula  laryngis,  297 
Cornua  of  cord,  240 

of  hyoid  bone,  78 
Corona  glandis,  326 
Coronal  suture,  25,  57 
Coronary  arteries,  189 

artery  of  stomach,  201 

ligaments  of  liver,  278 

plexus,  259 

sinus,  270 

valve,  183 
Coronoid  fossa,  54,  56,  97 

process,  99 
Corpora  albicantia.  229 

cavernosa,  325 

quadrigemina,  233 

striata,  230 


INDEX. 


397 


Corpus  Arantii,  184 

callosum,  231,  232 

dentatum,  237 

fimbriatum,232 

Highmori,  327 

luteuiu,  338 

S{)ongiosum,  325 
Corpuscles,  Paciuian,  341 

tactile,  341 
Corrugator  supercilii,  142 
Corti,  ganglia  of,  380 

membrane  of,  378 

organ  of,  378 

rods  of,  378 
Cortical  substance  of  kidney,  313 
Costal  cartilages,  83 
Costo-central  articulations,  122 
Costo-clavicular  line,  310 
Costo-transverse  articulations,  123 
Costo-vertebral  articulations,  122 
Cotyloid  cavity,  83 

ligament.  133 

notcb,  83 
Cowper's  glands,  324 
Cranial  ganglia,  244 

nerves,  241 

topography,  237 
Cranium,  bones  of,  22 
Cremaster  muscle,  328 
Cremasteric  artery,  330 

fascia,  382 
Crest  of  the  ilium,  85 

of  tibia,  110 
Cribriform  plute  of  ethmoid  bone, 

40 
Crico-arytenoideus  lateralis,  299 

posticus,  299 
Cricoid  cartilage,  295 
Crico-thyroideus,  299 
Crista  falciformis,  379 

galli,  40 

vestibuli,  373 
Crown  of  tooth,  200 
Crucial  ligament,  121,  134,  135 
Crura  of  penis,  325 
Crural  arch.  385 

canal,  383 

boundaries  of,  384 

nerve,  anterior,  253 
parts  around,  384 

ring,  384 

sheath,  385 
Crureus,  172 
Crus  cerel)ri,  229 


Crypts  of  Lieberkuhn,  274 
Crystalline  lens,  354 

structure  of,  355 
Cuboid  bone,  114 
Culmen,  237 
Cuneate  lobe,  228 
Cuneiform  bone,  103,  114 

cartilages,  297 
Cupola  of  cochlea,  374 
Curvatures  of  stomach,  270 
Curved  line,  28 
Cutaneous  nerves  of  arm,  250 
Cuticle,  341 
Cystic  duct,  282 

Daetos,  327 
Darwin,  tubercle  of,  364 
Decussation  of  pyramids,  235 
Dtitoid,  161 

tubercle,  90 
Demours,  membrane  of,  348 
Dental  canal,  44 

inferior,  56 

groove  of  Goodsir,  263 

papilla,  263 

ridge,  263 

fissure,  226 
Dentate  nucleus,  235 
Dentinal  fibers,  263 

tubes,  261 

tubules,  263 
Dentine,  261 
Dej^ressor  alje  nasi,  144 

anguli  oris,  144 

labii  inferioris,  144 
Derma,  341 

Descemet,  membrane  of,  348 
Descending  colon,  275 
Diagonal  line,  108 
Diameters  of  pelvis,  89 
Diai)hragni,  160 
Diaplivsis,  22 
Diartlirosis,  117,  118 
Digastric  fossa,  36 

muscle,  147 
Digestive  organs,  259 
Digital  depressions,  35 

fossa,  108 
Dilator  naris  anterior,  143 
posterior,  143 

pupilhe,  .351 
Discus  ])roligerus,  .338 
Dorsal  is  pedis  artery,  210 
Dorsi-spinal  veins,  217 


398 


INDEX. 


Dorso-lumbar  nerve,  2o2 
Dorsum  sclhe,  .'W 
Douglas's  poucl),  ;>.'>4 
Duct  of  Biutholin,  2G4 

common  bile-,  282 

cystic,  282 

ejaculiitory,  331 

of  Gartner,  339 

hepatic,  281 

lacrimal,  361 

lymphatic,  right,  221 

nasal,  362 

pancreatic,  284 

of  Eivinus,  265 

Stensen's,  265 

thoracic,  221 

thj'^ro-glossal,  266 

Wharton's,  265 
Ductless  glands,  284 
Ductus  cochlearis,  377 

communis  choledochus,  282 

endolymphaticus,  373 
Duodenum,  272 
Dura  mater,  240 

cerebral,  222 

sinuses  of,  214 

Ear,  363 

external,  363 

internal,  372 

middle,  365 
Ear-point,  364 
Ear-stones,  376 
Eighth  nerve,  246 
Ejaculatory  duct,  331 
Elbow-joint,  128 
Eleventh  nerve,  247 
Eminence  of  aqueductus   Fallopii, 
367 

ilio-pectineal,  87 
Eminentia  arcuata,  38,  60 

articularis,  35 

collateral  is,  231 
Emissary  veins  of  Santorini,  214 
Emulgent  vein,  316 
Enamel  cells,  263 

columns,  261 

membrane,  263 

organs,  263 

pulp,  263 

of  tooth,  261 
Enarthroses,  118 
Endocardium,  186 
Eudolymph,  375 


Endosteum,  19 
Ensiform  cartilage,  80 
Epenceidialon,  224 
Epicondyle  of  femur,  109 

of  humerus,  96 
Epidermis,  341 
Epididymis,  328 
Epigastric  artery,  deep,  205 
superficial,  208 
superior,  196 
region,  290 
Epiglottis,  297 

muscles  of,  300 
Epiphysis,  22 

cerebri,  233 
Equator  of  eye,  345 

of  lens,  354 
Equatorial  plane  of  eye,  345 
Erectile  tissue,  326 
Erector  clitoridis,  387 
penis,  387 
spinse,  152 
Esophageal  artery,  200 
Esophagus,  269 
Ethmoid  bone,  40 

articulations  of,  42 
centers  of  ossification  of,  42 
cells,  41 

process  of  inferior  turbinated, 
52 
Ethmoidal  canals,  25 
foramen,  64 
foramina,  58 
notch,  24 
spine,  31 
Ethmo-sphenoidal  suture,  64 
Eustachian  tube,  371 

opening  of,  368 
valve,  183 
Exoccipitale,  27 
Extensor  brevis  digitorum,  179 
hallucis,  179 
pollicis,  167 
carpi  radialis  longior,  165 

ulnaris,  166 
coccygis,  155 

communis  digitorum,  166 
indicis,  167 
longus  digitorum,  175 
hallucis,  175 
pollicis,  167 
minimi  digiti,  166 
ossis  metacarpi  pollicis,  166 
External  capsule,  230 


INDEX. 


399 


External  ear,  363 

oblique  muscle,  156 
Eye,  345 

appendages  of,  359 

coats  of,  346 

nerves  of,  358 
Eyeball,  345 

muscles  of,  355 
Ej'ebrows,  359 
Eyelashes,  360 
Eyelids,  359 

Facial  artery,  192 

nerve,  246 
Falciform  ligament  of  liver,  277,278 

process  of  Burns,  384 
Fallopian  tubes,  337 
False  pelvis,  88 

ribs,  80 

vertebrae,  69 
Falx  cerebelli,223 

cerebri,  2:22 
Fang  of  tooth,  260 
Fascia,  Buck's,  389 

Colics',  3«8,  389 

cremasteric,  382 

dentata,  232 

infundibuliform,  328 

intercolumnar,  328 

lata,  170 

lumbar,  158 

palmar,  167 

pelvic,  389 

plantar,  179 

recto-vesical,  389 
Fasciae,  141 

of  foot,  178 

of  hand, 167 

perineal,  388 
Fasciculus  teres,  334 
Fauces,  pillars  of,  264 
Female  generative  organs,  331 

perineum,  390 

urethra,  323 
Femoral  artery,  206 

common,  surgical  anatomy, 
213 

canal,  383 

hernia,  anatomy  of,  383 
coverings  of,  385 

ring,  384 

superficial,    surgical    anat- 
omy, 213 
Femur,  lOG 


Femur,  development  of,  109 

muscular  attachments  of,  109 
Fenestra  oval  is,  367,  373 

rotunda,  367 
Fibula,  112 
Fibular  nerve,  255 
Fifth  nerve,  243 

ventricle,  233 
Filiform  papillae,  266 
Filum  termiuale,  240 
Fimbriae  of  oviduct,  337 
First  nerve,  241 
Fissure,  auricular,  39 
calcarine,  226 
calloso-marginal,  226 
collateral,  226 
dentate,  226 
Glaserian,  35,  61,  367 
of  liver,  278 
longitudinal,  228 
of  liver,  278 
palpebral,  359 
parieto-occipital.  external,  225 

internal,  226 
petro-tympanic,  367 
pterygomaxillary,  69 
of  Eolando,  225 

location  of,  238 
sphenoidal,  60.  64 
spheno-maxillary,  64,  68 
of  Sylvius,  225 

location  of,  238 
transverse,  226 

of  liver,  278 
umbilical,  278 
Fissures,  cerebral,  225 
of  spinal  cord,  240 
Flat  bones,  function  of,  21 
Flexor  accessorius,  180 
brevis  digitorum,  179 
hallucis,  ISO 
minimi  digiti,  169,  181 
pollicis,  168 
carpi  radialis,  163 

ulnaris,  164 
longus  digitorum,  177 
hallucis,  177 
pollicis,  165 
]»rofundus  digitorum,  164 
siiblimis  digitorum,  164 
Fhmting  ril)S,  80 
Flocculus,  2'.i7 
Fhjod's  ligament,  127 
Folds  of  Houston,  276 


400 


INDEX. 


Folium  cacuniinis,  237 
Fontana,  spaces  of,  350 
Fontanels,  58 
Foot,  bones  of,  113 

muscles  of,  179 
Foramen  for  Arnold's  nerve,  38 

caicum,  58,  2UG 

of  frontal  bone,  24 

centrale  cocbleai,  380 

condj'lar,  anterior,  61 
posterior,  29 

condyloid,  posterior,  61 

ethmoidal,  58,  64 

intervertebral,  70 

for  Jacobson's  nerve,  38,  367 

jugular,  38 

lacerum  medium,  60 
posterius,  30,  61 

magnum,  29,  61 

of  Majendie,  240 

malar,  49 

mastoid,  36,  61 

medullary,  90,  99 
of  femur,  108 
of  radius,  100 

mental,  55 

of  Monro,  232 

obturator,  84 

optic,  34,  66 

ovale,  60 

of  sphenoid,  33 

parietal,  26 

rotundum,  32,  60 

sacral,  75,  76 

of  Scarpa,  47 

singulare,  379 

spheno-palatiue,  51,  67 

spinal,  72 

spinosum,  33,  60 

of  Stensen,  47 

stylo-mastoid,  39,  61 

supra-orbital,  23,  65 

thyroid,  84 

Vesalii,  33,  60 

of  Winslow,  293 
Foramina  Thesbesii,  183 
Forearm,  bones  of,  97 

muscle  of,  163 
Fornix,  232 

conjunctivfe,  360 
Fossa,  anterior,  of  skull,  58 

of  antihelix,  363 

canine,  44 

capitis,  106 


Fossa,  cerebral,  58 

coronoid,  97 

digastric,  36 

digital,  108 

glenoid,  94 

of  helix,  363 

iliac,  85 

incisive,  44 

infraorbital,  45 

infraspiuous,  91 

ischio-rectal,  385 

jugular,  30 

lacrimal,  24,  63 

nasal,  66 

uavicularis,  322 
female,  333 

olecranon,  97 

ovalis,  183,  384 

patellaris,  354 

pterygoid   34 

of  Rosenmiiller,  268 

scaphoidea,  363 

of  skull,  anterior,  58 
middle,  60 

sphenomaxillary,  69 

subarcuate,  61 

sublingual,  55 

submaxillary,  56 

subscapular,  91 

suprasjtinous,  91 

temporal,  67 

triangularis,  296 

trochlear,  24 

vesicalis,  278 

zygomatic,  68 
Fourchette,  333 
Fourth  nerve,  242 

ventricle,  234 
Fovea  centralis,  352 

hemielliptica,  373 

hemispherica,  373 
Frenum  linguae,  266 

preputii,  326 
Frontal  bone,  22 

articulations  of,  25 
centers  of  ossification  of,  25 
muscles  from,  25 

crest,  24 

eminences,  23 

lobe,  225 

process,  49 

sinuses,  23,  25 

sulcus,  24 
Fron  to-malar  suture,  64 


INDEX. 


401 


Fronto-parietal  suture,  57 
Frouto-sphenoidal  suture,  64 
Fuudameutal  laniellai,  19 
Fungiform  pai>illa?,  266 
Fuuiculus  cuueatus,  235 

gracilis,  235 

of  Rolando,  235 

Gaertnek,  duct  of,  339 
Gall-bladder,  282 
Ganglion,  Arnold's,  244 

of  Bochdalek,  244 

cervical,  256,  257 

ciliary,  244 

coccvgeal,  256 

of  Corti,  380 

Gasserian,  243,  244 

impar,  256 

otic,  244 

of  Ribes,  256 

spheno-palatine,  244 

spirale,  375,  380 

submaxillary,  245 

of  Valentin^  244 
Gangli<mic  layer  of  retina,  352 
Gasserian  ganglion,  243,  244 
Gastric  artery,  201 
Gastrocnemius,  176 
Gastro-colic  omentum,  293 
Gastro-hepatic  omentum,  293 
Gastro-splenic  omentum,  294 
Gemellus  inferior,  174 

superior,  174 
Generative  organs,  female,  331 

male,  324 
Genial  tubercles,  55 
Geniobyoglossus,  147 
Geniobyoid  muscle,  1  17 
Genitocrural  nerve,  253 
Germinal  spot,  338 

vesicle,  '.V.iH 
Gimbernat's  ligament,  156 
Ginglvmus,  118 
GhibeJbi,  23,  237 
(iladiolus,  80 
(iland,  lacriinal,  361 

lingual,  2(56 

mammary,  339 

l>arotid,  264 

j)n)statc,  324 

sublingual,  265 

submaxillary,  2()5 

tbymiis,  287 

thyroid,  286 

20 


Glands  of  Bartholin,  333 

Brunner's,  274 

Cowper's,  324 

ductless,  284 

of  Littre,  323 

Meibomian,  360 

of  Moll,  360 

parathyroid,  287 

Peyer's,  274 

salivary,  264 

sebaceous,  342 

solitary,  274 

sweat-,  342 

Tyson's,  326 
Glandulse  Tysonii  odoriferae,  326 
Glans  penis,  326 
Glaserian  fissure,  35,  61,  367 
Glenoid  fossa,  35,  94 

ligament,  127 
Glisson,  capsule  of,  276,  279,  281 
Glosso-ei)iglottic  folds,  297 
Glosso-pharyngeal  nerve,  247 
Glottis,  298 
Gluteal  artery,  205 

lines,  85 

nerves,  254 
Gluteus  maximus.  173 

medius,  173 

minimus,  173 
Gomphosis,  118 
Graafian  follicles,  337,  338 
Gracilis,  172 

Groove,    auriculo-veutricular,    182, 
183 

bicipital,  95 

infraorbital,  64 

sacral,  76 

spiral,  95 

sub(;lavian,  90 
Gubernaculum  testis,  331 
(Gustatory  cells,  343 

pore,  343 
Gyri  226 
Gyrus  fornicatus,  226 

HAiR-bulb,  :i42 

H<air-('(lls  of  ('orti's  organ,  378 

Hair-follicle,  312 

Hair-pa|)illa,  342 

Hairs,  341 

Hammer,  MM 

Hamstring,  inner,  175 

outer,  174 
Hamular  process,  34,  48,  375 


402 


INDEX. 


Hand,  bones  of,  102 

iasciaj  of,  1(J7 

muscles  of,  1G8 
Hard  palate,  2t)3 
Hasiier,  valve  of,  3(32 
Haversian  canals,  18 

system,  18 
Head,  hones  of,  22 

of  bone,  21 

of  femur,  10() 

of  fibula,  112 

of  humerus,  95 

muscles  of,  142 

of  radius,  10© 

of  rib,  81 

of  tibia,  110 

veins  of,  214 
Heart,  182 

structure  of,  186 

veins  of,  220 
Helicine  arteries,  326 
Helicis  major,  364 

minor,  364 
Helicotrema,  374 
Helix,  363 
Hemiarthrosis,  117 
Henle's  looj),  313 
Hensen's  line,  140 
Hepatic  artery,  202,  281 

duct,  28l" 

veins,  280 
Hepato-duodenal  ligament,  293 
Hernia,  femoral,  anatomy  of,  383 

inguinal,  anatomy  of,  381 
Hesselhach's  triangle,  383 
Hey's  ligament,  384 
Hiatus  Fallopii,  38,  (JO 
Highmore,  antrum  of,  43,  46 
Hilum  of  kidney,  313 

of  liver,  278 

of  lung,  304 

of  spleen,  285 
Hii)-joint,  132 
Hippocampus  major,  231 
Histology,  definition  of,  17 
Horizontal  i)late  of  palate  bone,  52 
Horner's  muscle,  142 
Houston's  folds,  276 
Huguier,  canal  of,  86,  367 
Humerus,  95 

development  of,  97 

muscular  attachments  of,  97 
Humors  of  eye,  346,  354 
Hunter's  canal,  172 


Hyaloid  canal,  354 

membrane,  354 
Hydatids  of  Morgagni,  329 
Hymen,  333 
Hyoglossus,  148 
Hyoid  bone,  78 

Hypochondriac  regions,  290,  292 
Hypogastric  artery,  204 

plexus,  259 

region,  291 
Hypoglossal  nerve,  248,  267 

Ileo-cecal  valve,  273 
Ileum,  273 
Iliac  artery,  204 

common,  203 

surgical  anatomy,  212 
deep  circumflex,  206 
external,  205 
internal,  203 

surgical  anatomy,  213 
superficial  circumflex,  208 

fossa,  85 

vein,  common,  219 
internal,  219 
Iliacus,  170 
Ilio-costalis,  152 
Ilio-fcniorul  ligament,  132 
Ilio-hypogastric  nerve,  252,  253 
Ilio-inguinal  nerve,  253 
Ilio-lumbar,  artery,  205 
Ilio-pectineal  eminence,  87 

line,  87 
Ilio-tibial  band,  170 
Ilium,  85 

Impression,  rhomboid,  91 
Incisive  fossa,  44 
Incisor  crest,  47 

fossa,  55 

teeth,  261 
Incisura  cerebelli,  236 

intertragica,  363 
Incus,  368 

Inferior  curved  line,  28 
Infracostales,  159 
Infraorbital  artery,  357 

groove,  45,  64 
Infras|)inatus,  162 
Infraspinous  fossa,  91 
Infratemporal  ridge,  33 
Iiifnndibula  of  lungs,  307 
Infundibuliform  fascia,  328 
Infundii)ulum,  229 

of  cochlea,  374 


INDEX. 


403 


Inguinal  canal,  381 

boundaries  of,  382 
hernia,  anatomy  of,  381 
external  oblitjue,  383 
internal  or  direct,  383 
regions,  290,  292 
Inion,  237 

Innominate  artery,  189 
bone,  83 
veins,  216 
Insertion  of  muscle,  141 
Interclavicular  notch,  80 
Intercolumnar  fascia,  328 
Intercostal  arteries,  201 
superior,  196 
muscles,  external,  159 
internal,  159 
Interlobular  arteries,  315 

veins,  280 
Intermediate  disk,  140 
Internal  capsule,  230 
ear,  372 

oblique  muscle,  156 
Interossei,  dorsal,  169 
of  foot,  181 
palmar,  169 
plantar,  181 
Interosseous  border,  100 
ligament,  125 

of  carpus,  131 
membrane  of  arm,  130 

of  leg,  136 
nerves  of  arm,  251 
ridge,  110 
Interparietal  bone,  27 

suture,  57 
Interphalangeal  articulations,  132 
Inters])inales,  155 
Interstitial  lamellse,  18 
Intertransversalcs,  155 
Intertrochanteric  lines,  108 
Intertubular  substance,  261 
Intervertebral  fibrocartilage  or  disk, 
119 
foramina,  70 
Intestine,  large,  274 

blood-  and  nerve-supply  of, 
276 
small,  272 

blood-vessels  of,  274 
coats  of,  273 
glands  of,  274 
iM'rv(!S  of,  274 
Intumescentia  gangliaformis,  380 


Iris,  350 

Ischio-cavernosus,  387 
Ischiorectal  fossa,  385 
Ischium,  86 
Isthmus  faucium,  264 

of  thyroid,  86 

tubfe,  371 
Iter  chordai  anterius,  367 
posterius,  367 

Jacob's  membrane,  353 
Jacobson's  nerve,  370 
Jejunum,  273 

Joints,  nerve-supply  of,  119 
Jugular  foramen,  38 

fossa,  30,  38 

notch,  29 

process,  29 

veins,  215 

Kerato-cricoideus,  300 
Kidney,  312 

nerves  of,  317 

relations  of,  312 

size  and  weight,  312 
Knee-joint,  133 
Krause's  membrane,  140 

Labia  majora,  332 

minora,  332 
Labyrinth,  372 

membranous,  375 

osseous,  372 
Lacrimal  appa vatus,  361 

artery,  357 

bones,  48 

canal,  46,  48 

canaliculi,  361 

ducts,  361 

fossa,  24,  63 

gland,  361 

nerve.  358 

notcli,  45 

papilla^  360 

process  of  inferior  turbinated, 
52 

sac,  362 

tubercle,  46 
Lacrimo-ethmoidal  suture,  64 
Lac  teals,  220 
Lacuna  magna,  323 
Lacunic  of  l)one,  18 
Lacus  hicrimalis,  360 
Laml)da,  237 


404 


INDEX. 


L:iiub(l(»i(l  suture,  25,  57 
Lamellct;  of  bone,  18 

circuuiferential,  19 

concentric,  IW 

fundamental,  19 

interstitial,  18 
Lamina  cinerea,  "228 

cribrosa,  38,  347,  372,  379 

fossa,  347 

recticularis,  379 

spiralis,  375 

suprachoi'oidea,  348 

terminal  is,  229 

vitrea,  349 
Lamime  of  vertebra,  71 
Large  intestine,  274 
Laryngeal  nerve,  256.  301 

'poucb,  299 
Larynx,  295 

arteries  and  veins  of,  300 

cartilages  of,  295 

ligaments  of,  297 

muscles  of,  299 

nerve-supply  of,  301 

ventricle  of,  299 
Lateral  ligaments  of  liver,  278 

masses  of  ethmoid  bone,  41 

ventricles,  231 
Latissimus  dorsi,  150 
Left  auricle,  184 

ventricle,  185 
Leg,  muscles  of,  175 
Lens,  crystalline,  354 
Lenticular  nucleus,  230 
Levator  anguli  oris,  144 

ani,  3S7 

glandulpe  thyroidese,  286 

labii  inferioris,  144 
superioris,  144 

alseque  nasi,  143 

palati.  148 

palpebrse  superioris,  142 

scapulae,  150 
Levatores  costarum,  159 
Ligament,  annular,  anterior,  167 
of  foot.  178 
external,  of  foot,  179 
internal,  of  foot,  178 
posterior,  167 
of  wrist,  130 

anterior,  of  ankle.  137 
common.  119 
of  elbow,  128 

atlanto-axial,  120 


Ligament,  Vjroad,  of  liver,  277 

of  uterus,  3.35 
calcaneo-astragaloid,  137 
calcaneo-cuboid,  138 
calcaneo-navicular,  138,  139 
capsular,  119 

of  hip,  132 

of  ossicles,  369 
check,  121 

chondro-clavicular,  126 
cbondro-sternal,  123 
chondro-xiphiod,  124 
coraco-acromial,  127 
coraco-clavicular,  127 
coraco-humeral,  127 
coronary,  of  liver,  278 
cotyloid,  133 
crucial,  120.  134,  135 
deltoid,  137 

falciform,  of  liver,  277,  278 
Flood's,  127 
Gimbernat's,  156 
gleno-humeral,  127 
glenoid,  127 
hepato-duodenal,  293 
Key's,  384 
ilio-femoral,  132 
ilio-luniV»ar,  124 
infraspinous,  119 
interclavicular,  126 
interosseous,  125 

of  corpus,  131 
intertransverse,  119 
long  internal  lateral,  122 
oblique,  of  arm,  130 
obturator,  126 
occipito-atlantal,  120 
occi  pi  to-axial.  121 
occi  pi  to-cervical,  121 
occipito-odontoid,  lateral,  121 
orbicular,  129 
phreno-colic,  285 
posterior,  of  ankle,  137 

common,  119 

of  elbow,  128 
Pou  part's,  156,  170,  382 
pubo-prostatic,  319 
radio-carpal,  1.30 
radio-ulnar,  129 
r(>cto-uterine.  335 
rhomboid,  126 
round,  of  liver,  278 

of  uterus,  336 
sac lo  coccygeal,  125 


INDEX. 


405 


Lij^ament,  sacro-iliac.  125 
sacro-luin])ar,  124 
sacro-sciatic,  12.") 
short  internal  lateral,  122 

vertebral,  119 
spheno-mandibular,  122 
spino-glenoid,  127 
stellate,  123 
stylo-maxillary,  122 
suprapubic,  126 
supraspinous,  119 
suspensory,  of  incus,  369 
of  lens,  355 
of  liver,  277,  278 
of  malleus,  368 
of  penis,  325 
of  si)leen,  2S5 
thyro-epis^lottic,  297 
tibio-fibular,  136 
transverse,  of  hip,  133 
of  knee-joint,  135 
trapezoid,  127 
triangular,  389 
vesico-uterine,  335 
of  Wrisberg,  135 
Y-,  132 
Ligamenta  alaria.  135 
Ligaments  of  bladder,  319 
intersternal,  124 
lateral,  of  liver,  278 
of  larynx,  297 
of  ossicles,  368 
palmar,  131 
of  scapula,  127 
of  Schlemin,  127 
of  sternum,  124 
tarsal,  360 
of  uterus.  335 
Ligamentum  arcuatum,  134 
externum,  158 
denticiilatnm,  240 
latum  pulmonis,  308 
mucf)sum,  135 
nuclue,  150 
patellfE,  134 

pectinntum  iridis,  348,  350 
spirale,  378 
subflavum,  119 
suspensorium,  122 

oculi,  346 
t'-ris.  133 
Winslowii.  134 
I>iml)ic  IoIk;,  227 
Limbus  laminte  spiralis,  377 


Line,  diagonal,  108 
Hensen's,  140 
ilio-pectirieai,  .'-7 
intertrochanteric,  108 
Linea  alba,  156 
aspera,  108 
axillaris,  310 
eminens,  296 
niammillaris.  310 
mediana,  310 
parasternalis   310 
quadrat  i,  108 
scapularis,  310 
splendens,  240 
sternalis,  310 
stern  o- costal  is,  310 
Lingual  arterv,  191 
glands,  206 
lobule,  305 
nerves,  266 
tonsil,  266 
Lingualis,  148 
Lingula,  233,  237 
Liquor  folliculi,  338 

Morgagni.  355 
Lisfranc's  tubercle,  82 
Lithotomy,  i)arts  divided  in,  390 
Liver,  276 

blood-vessels  of,  279 
lobes  of,  279 
nerves  of,  281 
relations  of,  282 
structure  of,  281 
Lobes  of  cerebellum,  236 
of  cerel)rum,  225 
of  liver.  279 
Lobus  caudatus,  279 
centralis,  237 
quad  rat  us,  279 
Spigelii,  279 
Locus  cffruleus,  234 
I  Long  bones,  20 
,  Longissimus  dorsi,  153 
I  Longitudinal  fissure,  228 
'  Longus  colli,  1  19 

Lower  extremity,  veins  of,  218 
'  Lower,  tubercle  of,  183 
j  Lumbar  arterv,  203  . 
t  fjiscia,  158 

I  nerves,  252 

plexus,  252 
I  regions,  290,  292 

Liimbo-sacral  cord,  252 
Lumbricales,  l(i9,  180 


406 


INDEX. 


Lungs,  303 

structure  of,  300 

toi)ognii)hical   anatomy  of,  309 

vessels  and  nerves  of,  307 
Lunula  of  nail,  341 
Lvni]>liatic  duct,  right,  221 

glands,  220 
Lynii)liatics,  220 
Lvniph-spaces  of  eyeball,  358 
Lyra,  232 

Macula  acustica,  376 

lutea,  351 
Malar  bone,  49 
canal,  (J4 
foramina,  49 
process  of  superior  maxillary, 

46 
tuberosity,  49 
Male  generative  organs,  324 

urethra,  321 
Malleolus,  external,  112 

internal,  110 
Malleus,  368 

Malo-maxillary  suture,  64 
Malpighian  bodies,  236 
body,  315 
tuft,  313,  315 
Mam m 06,  339 

Mammayy  artery,  accessory  exter- 
nal, 198 
internal,  196 
glands,  339 

vessels  and  nerves  of,  340 
Mandible,  54 
Manubrium,  80 

of  malleus,  368 
^larginal  convolutions,  226 
Marrow  of  bone,  19 
Masseter,  145 

Mastoid  antrum,  location  of,  238 
cells,  36 
foramen,  36,  61 
portion  of  temporal  bone,  36 
process,  36 
Masto-occipital  suture,  57 
Masto-parietal  suture,  57 
Matrix  of  nail*  341 
Maxillary  bane,  inferior,  54 

articulation  of,  56 
centers   of  ossification 

of,  56 
muscular     attachment 
of,  57 


Maxillary  bone,  superior,  43 

articulations  of,  48 
centers  of    ossification 

of,  48 
muscular   attachments 
of,  48 
nerve,  inferior,  243 

superior,  243 
process,  49,  51 

of  inferior  turbinated,  52 
sinus,  46 
tuberosity,  44 
Meatus  auditorius  externus,  37 
internus,  38,  60 
of  nose,  inferior,  67 
middle,  67 
superior,  67 
urinarius,  323,  326 
female,  332 
Meatuses  of  the  nose,  67 
Median  nerve  of  arm,  250 
Mediastinal  artery,  posterior,  201 
Mediastinum,  303 

testis,  327 
Medulla  of  bone.  19 

oblongata,  235 
Medullary  artery,  19,  21,  198 
canal  of  bone,  18 
of  humerus,  95 
of  tibia,  110 
foramen,  90,  99 
of  femur,  108 
of  radius,  100 
substance  of  kidney,  313 
Medulli-spinal  veins,  2i8 
Meibomian  glands,  360 
Membrana  basilaris,  377,  378 
fiaccida,  365 
granulosa,  338 
limitans  interna,  352 
pupillans,  351 
tectoria,  378 
tympani,  365 

secondaria,  367 
Membrane  of  Bowman,  348 
of  Bruch,  349 
of  Descemet,  348 
hyaloid,  .354 
.    of  Corti,  378 
interossous,  130 
Jacobs',  353 
Krause's,  140 
of  Miiller,  353 
of  Reissuer,  377 


INDEX. 


407 


Membrane,  Schneiderian,  343 

Schrapiieirs,  365 

vitelline,  338 
Membranous  canal  of  cochlea,  377 

labyrinth,  375 

urethra,  322 
Meningeal  artery,  middle,  location 

of,  238 
Meningo-rachidian  veins,  218 
Mental  foramen,  55 

process,  55 

tubercle,  55 
Meridional  plane  of  eye,  345 
Mesencephalon,  224 
Mesenteric  artery,  inferior,  202 

superior,  202 
Mesenteries,  294 
Mesocecum,  294 
Mesocolon,  294 
Mesogastrium,  294 
Mesorectum,  275,  294 
Metacarpal  bones,  104 
Metacarpo-phalangeal  articulations, 

132 
Metatarsal  artery,  210 

bones,  114 
Metatarsus,  synovial  sacs  of,  139 
Metencephalon,  224 
Middle  ear,  365 

fossa  of  skull,  60 
Milk  teeth,  260 
Mitral  valve,  182,  185 
Modiolus,  374 
Molar  teeth,  261 
Moll,  glands  of,  360 
Monro,  foramina  of,  232 
Mons  Veneris,  332 
Motor  oculi,  242 
Mo  to  rial  end-plates,  222 
Mouth,  263 

Miiller,  membrane  of,  353 
Multifidus  spinai,  155 
Muscle,  140 

ciliary,  349 

Homer's,  142 

intercostal.  159 

origin  and  insertion  of,  141 
Muscles  of  abdomen,  15() 

of  ba<;k,  150 

of  ei)iglottis,  .300 

of  Eustachian  tube,  .371 

of  fixternal  ear,  364 

of  cvcball,  .355 

of  foot,  179 


Muscles  of  forearm,  163 
of  hand, 168 
of  head,  142 
of  larynx,  299 
of  leg,  175 

of  lower  extremity,  169 
of  neck,  145 
of  perineum,  386 
of  shoulder  and  arm,  161 
of  thorax,  1.59 
of  tympanum,  369 
of  ureters,  320 
vertebral,  149 
Muscular  nerve  of  brachial  plexus, 
250 
of  internal  popliteal,  254 
of  posterior  tibial,  255 
of  sacral  plexus,  254 
tissue,  varieties  of,  140 
Musculi  papillares,  184 

pectinati,  183 
Musculo-cutaneous   nerve  of   arm, 

250 
Musculo-phrenic  artery,  196 
Musculo-spiral  nerve,  251 
Musculus  accessorius  ad   iliocosta- 
lem,  1.53 
of  leg,  255 
Mylohyoid  groove,  56 
muscle,  147 
ridge,  .56 
Myrtiform  fossa,  44 

Nails,  .341 
Nares,  66 
Nasal  bones,  43 

crest,  47 

duct,  362 

eminence,  23 

fossae,  66 

blood-vessels  of,  344 

meatus,  42 

mucous  membrane,  343 

notch,  23 

process,  23 

of  superior  maxillary,  46 

septum,  67 

spine,  23 

anterior,  47 
l)osterior,  52 
Nasi  on,  237 

Naso-|)aIatine  groove,  .54 
Navicular  bone,  114 
Neck  of  femur,  106 


408 


INDEX. 


Neck,  muscles  of,  145 

of  rib,  81 

of  tooth,  260 

veins  of,  214 

Nerye,  abducens,  24G 

articular,  of  internal  popliteal, 

254 
auditory,  246,  379 
cardiac,  inferior,  257 

superior,  256 
ciliary,  358 
circumflex,  250 
cochlear,  380,  379 
crural,  anterior,  253 
cutaneous,  of  arm,  250 
dorso-lumbar,  252 
eighth,  246 
eleventh,  247 
facial,  246 
fibular,  255 
fifth,  243 
first,  241 
fourth,  242 
genito-crural,  253 
glosso  pliaryngeal,  247 
gluteal,  254 
hypoglossal,  248,  267 
ilio  hypogastric,  252,  253 
ilio-inguinal,  253 
interosseous,  of  forearm,  251 
Jacobson's,  370 
lacrimal,  358 
laryngeal,  256 
lingual,  266 
maxillary,  inferior,  243 

superior,  243 
median,  of  arm,  250 
muscular,  of  internal  jtopliteal, 
254 

of  posterior  tibial,  255 
musculo-cutaneous,  of  arm,  250 

of  leg,  255 
musculo-spiral,  251 
ninth,  247 
obturator,  253 
olfactory,  24 J.  344 
ophthalmic.  243 
optic,  241,  358 
petrosal,  245 
pharyngeal,  256 
phrenic,  249 
plantar,  255 
pneumogastric,  247 
popliteal,  external,  255 


Nerve,  popliteal,  internal,  254 

pudic,  254 

radial,  251 

sacral,  256 

sciatic,  254 

second,  241 

seventh,  246 

sixth,  246 

spinal  accessory,  247 

splanchnic,  258 

subscapular,  250 

suprascapular,  250 

sympathetic,  256 

tenth,  247 

third,  242 

tibial,  anterior,  255 
posterior,  255 

trifacial,  243 

trochlear,  242 

twelfth,  248 

tympanic,  370 

ulnar,  251 

vagus,  247 

vestibular,  .380 

Vidian,  345 

of  Wrisberg,  250 
Nerve-fiber  layer,  .3.52 
Nerve-tissue,  structure  of,  221 
Nerves,  coccygeal,  256 

cranial,  241 

of  auricle.  364 

of  bladder,  321 

of  choroid,  349 

of  Eustachian  tube,  372 

of  eye,  .358 

of  eyelids,  .360 

of  iris,  351 

of  kidney,  317 

of  Lancisi,  2.32 

of  larynx,  301 

luuibar,  2.52 

of  lungs,  .308 

of  mamma".  340 

of  membrana  tympani,  366 

of  nose,  344 

of  ocular  muscles,  357 

of  penis,  327 

spinal,  248 

of  testicle.  .3.30 

tlioracic,  2.52 

of  trachea.  .303 

of  tympanum,  .370 

of  uterus,  .337 
Nervous  system,  221 


INDEX. 


409 


Nervus  fuscalis,  252 

Xeuri lemma,  222 

Ninth  nerve,  247 

Nipple,  339 

Nodal  point,  345 

Nodulus,  237 

Nose,  blood-vessels  of  exterior,  343 

nerves  of,  344 
Notch,  cotyloid,  83 

interclavicular,  80 

popliteal,  110 

of  Rivinus,  3(J5 

sacro-sciatic,  greater,  85 

supra-orbital,  23 

suprascapular,  94 
Notches,  vertebral,  70 
Nucleus  amygdalse,  230 

caudate,  230 
Nymphse,  332 

Obex,  234 

Oblique  line  of  clavicle,  90 
external,  55 
internal,  56 
of  scapular,  91 
Obliquus  auris,  304 

capitis  inferior,  156 

superior,  156 
inferior,  356 
superior,  356 
Obturator  artery,  204 
externus,  174 
foramen,  84 
internus,  174 
ligament,  120 
nerve,  253 
Occipital  artery,  192 
bone,  27 

articulations  of,  30 
centers  of  ossification  of,  31 
crest,  internal,  30 
groove,  36 
lobe,  220 
protuberance,  external,  28 

internal,  30 
sinuses,  30 
Occipito-atlantal    articulation,    119 
Occipto-frontalis,  142 
Ofr'ii»ito-pari(!tal  suture,  57 
Odontoblasts,  202 
Olecrajion  fossa,  97 

process,  99 
Olfactory  l)ulbs,  232 

cells  of  Scliultze,  :i43 


Olfactory  grooves.  31,  40 

nerve,  241,  344 
Olivary  body,  235 

process,  32 
Omentum,  gastro-colic,  293 

gastro-hepatic,  293 

gastro-splenic,  294 

great,  293 

lesser,  293 
Omo-hyoid  muscle,  147 
Opercula,  226 
Ophthalmic  artery,  194,  357 

nerve,  243 
Opponens  minimi  digiti,  169 

poUicis,  108 
Optic  chiasm,  242 

commissure,  228 

foramen,  32,  34,  GG 

groove,  31 

nerve.  241,  358 

origin  and  course  of,  359 

thalamus,  230 

tracts,  359 
Ora  serrata,  351 
Orbicular  ligament.  129 
Orbicularis  oris,  144 

palpebrarum,  142,  360 
Orbital  cavities,  01 

foramina,  external,  34 

lobe,  225 

plates,  24 

process,  49 
Organ  of  Corti,  378 

of  Rosen raiiller,  339 
Origin  of  muscle,  141 
Os  calcis,  113 

magnum,  104 

orbiculare,  308 

planum,  41 

unguis,  48 

uteri,  externum.  335 
internum.  335 
Osseous  labryinth,  372 
Ossicles,  ligaments  of.  308 

of  tymi)anum.  3(iS 
Ossification,  center  of.  19,  20 
Osteoblasts,  19.  20 
Osteology,  definition  of.  17 
Ostium  abdominale,  337 
Otic  ganglion,  244 
Otocojiia,  370 
Otoliths.  370 
Outh't  of  jMdvis.  89 
Oval  window,  367 


410 


INDEX. 


Ovarian  arteries,  339 

artery,  203,  33G 

nerves,  339 
Ovaries   337 
Ovicapsule,  338 
Oviducts,  337 
Ovisacs,  338 
Ovoidal  facets,  110 
Ovula  Nabothi,  336 
Ovum,  338 

Pacchionian  bodies,  223 

depressions,  26 
Pacinian  corpuscles,  341 
Palatal  muscles,  148 
Palate  bone,  50 

center  of  ossification  of,  52 

hard,  263 

process  of  superior   maxillary, 
45,  47 

soft,  264 
Palatine  canal,  accessory  posterior, 
52 
anterior,  47 
posterior,  44 

fossa,  anterior,  47 
Palato-glossus,  148 
Palato-maxillary  suture,  64 
Palato-pharyngeus,  148 
Palinur  fascia,  167 
Palniaris  brevis,  169 

longus,  164 
Palpebral  arteries,  357 

fissure,  359 
Pampiniform  plexus,  330 
Pancreas,  283 

lesser,  284 
Pancreatic  duct,  284 
Papilla  Vateri,  282 
Papillfe  of  tongue,  266 
Papillary  layer,  341 
Paracentral  lobe,  228 
Parallel  fissure,  location  of,  239 
Paramastoid,  29 
Parathyroid  glands,  287 
Parietal  bone,  25 

development  of,  26 

eminence,  25 

foramen,  26 

fossa,  26 

lobe,  225 
Parietooccipital   fissure,   external, 
225 
internal,  226 


Paricto-occipital  fissure,  location  of, 

23!) 
Parotid  gland,  264 
Parovarium,  339 
Pars  ciliaris  retina,  351,  352 

intermedia,  333 

iridica  retina;,  351 

optica  retinae,  351 
Patella,  109 
Patheticus,  242 
Pectineus,  172 
Pectoralis  major,  161 

minor,  161 
Pedicles  of  vertebra,  70 
Peduncles  of  cerebellum.  235,  237 
Pelvic  bones,  83 

development  of,  88 

fascia,  389 

plexuses,  259 
Pelvis,  88 

diameters  of,  89 

differences   between  male  and 
female,  89 

of  kidney,  313 
Penis,  325 

blood-vessels  and  nerves  of,  326 
Perforated  space,  anterior,  229 

posterior,  229 
Perforating  fibers  of  Sharpey,  19 
Pericardial  arterj",  200 
Pericardium,  181 
Perilymph,  372 
Perimysium,  140 
Perineal  fasciae,  388 
Perineum,  385,  386 

female,  390 
Perineurium,  222 
Periosteum,  19 
Peritoneum,  292 
Permanent  teeth,  260 

appearance  of,  262 
Peroneal  artery,  210 

bone,  112 
Peroneus  brevis,  178 

longus,  178 

tertius,  175 
Perpendicular    plate    of    ethmoid 

bone,  41 
Pes  accessor i us,  231 
Petit,  canal  of,  355 
Pctro-occipital  suture,  57 
Petrosal  nerves,  245 

process,  32 
Petro-sphenoidal  suture,  57 


INDEX. 


411 


Petro-tym panic  fissure,  367 
Petrous  portion  of  temporal  bone,  37 
Fever's  glands  or  patches,  274 
Phalangeal  processes,  379 
Plialaijges,  106 

of  foot,  117 
Pharyngeal  artery,  ascending,  192 

bursa,  268 

muscles,  268 

nerve,  256 

spine,  30 

tonsil,  268 
Pharyngo  epiglottic  fold,  297 
Pharynx,  267 

arteries  of,  269 

constriction  of,  268 

nerves  of,  269 
Phrenic  artery,  inferior,  202 

nerve,  249 
Phreno-colic  ligament,  285 
Pia  mater,  223,  240 

testis,  327 
Pigmentary  layer  of  retina,  353 
Pillars  of  fauces,  264 
Pineal  gland,  233 
Pinna,  363 
Pisiform  bone,  104 
Pituitary  body,  229 

membrane,  343 
Plantar  artery,  external,  211 
internal,  211 

fascia,  179 

nerves,  255 
Plantaris,  177 
Platvsma  mvoides,  145 
PleuVfe,  308  ' 

topographical  anatomy  of,  309 
Pleural  cavity,  308 

sinus,  308 
Plexus,  aortic,  259 

})rachial,  249 

cardiac,  great,  258 
superficial,  259 

carotid,  257 

cavernous,  257 

cervical,  248 

coronary,  259 

hypogastric,  259 

lutn1);ir,  252 

panipinifonu,  330 

renal,  :)17 

sacral,  253 

solar,  25H 

tympanic,  370 


Plexuses,  pelvic,  259 
Plica  epigastriea,  383 

semilunaris,  361 

uracil  i,  319 

ureterica,  321 
Pneumogastric  nerve,  247 
Pons  hepatis,  278 

Varolii.  234 
Popliteal  artery,  208 

nerve,  external.  2.55 
internal,  254 

notch,  110 

space  of  femur,  108 
Popliteus,  177 
Porta  hepatis,  278 
Portal  canals,  282 

system  of  veins,  219 

vein,  279 
Porus  opticus,  352 
Poupart's  ligament,  156,  170,  382 
Prtpuce,  326 

Primary  areolae  of  ossification,  20 
Process,  acromion,  92 

alveolar,  46 

angular,  of  frontal  bone,  23 

auditorv,  external,  37 

basilar,' 29 

clinoid,  32 

condyloid,  54 

coracoid,  9.3 

coronoid,  54,  56,  99 

ethmoidal,    of    inferior    turbi- 
nated, 52 

of  fibula  112 

frontal.  49 

hamular,  48.  375 

of  Ingrassias.  34 

laci-imal,  of  inferior  turbinated, 
52 

malar,  46 

mastoid,  36 

maxillary.  49,  57 

mental,  5.5 

nasal,  46 

of  frontal  bone,  23 

olecranon,  99 

olivary,  .32 

orbital,  49 

palate,  47 

pterygoid.  34,  51 

si>h('noidal,  51 

styhiid,  .39.  99,  100 

unciform.  41 

/.vgoniatic,  35,  49 


412 


INDEX. 


Processes  of  bone,  21 
ciliary,  349 
phalangeal,  379 
nngnal,  106 
vermiform,  23G 
of  a  vertebra,  71 
Processns  brevis  of  mallens,  368 
cochleariformis,  39,  61,  368 
gracilis  of  malleus,  368 
tubae,  34 
Profunda  cervicis,  197 
femoris,  208 
inferior,  198 
superior,  198 
Promontory  of  sacrum.  76 

of  tympanum,  364 
Pronator  quadratus,  165 

teres,  163 
Prosencephalon,  224 
Prostate  gland,  324 
Pi'ostatic  sinus,  322 

urethra,  321 
Psoas  magnus,  169 

parvus,  170 
Pterygoid  fossa,  34 

muscle,  external,  145 

internal,  145 
processes,  34,  51 
tubercle,  34 
Pterygo-maxillary  fissure,  69 
Pterygo-palatine  canals,  32 

grooves,  32,  52 
Pubes,  87 
Pubic  spine,  87 
Pubo-prostatic  ligament,  319 
Pudendum,  331 

Pudic  artery,  inferior  external,  208 
internal,  204 
superior  external,  208 
nerve,  254 
Pulmonary  artery,  187 
semilunar  valves,  184 
valve,  182 
veins,  220 
Pulp-cavity,  260 
Pulp  of  tooth,  261 
Punctum  lacrimale,  360 
Pupil,  350 
Pylorus,  270 
Pyramid  of  tbyroid,  286 

of  tympanum,  367 
Pyramidal  eminence,  373 

tracts,  235 
Pyramidalis,  158 


Pyramidalis  nasi,  143 
Pyramids  of  Fi;rrein,  315 

of  Malpighi,  .il'.i 

of  medulla  oblongata,  235 
Pyramis,  237 
Pyriformis,  173 

Quadrate  lobe,  227 
Quadratus  femoris,  174 

lumborum,  158 
Quadriceps  femoris,  172 

Radial,  artery,  199 

nerve,  251 
Radio-ulnar  articulations,  129 
Radius,  100 

development  of,  100 
muscular  attachments  of,  102 
Rami  of  inferior  maxillary  bone,  56 
Ramus  of  ischium   87 
Recto-uterine  ligament,  335 

pouch,  335 
Recto-vesical  fossa,  389 
Rectum,  275 
Rectus  abdominis,  158 

capitis  anticus  minor,  149 
posticus  major,  155 
minor,  155 
ex  tern  us,  356 
femoris,  170 
inferior,  355 
in  tern  us,  356 
lateralis,  149 
superior,  355 
Red  marrow,  19 
Regions,  abdominal,  290 
Reissner,  membrane  of,  377 
Renal  artery,  202,  315 
circulation,  315 
plexus,  317 
vein,  316 
Restiform  bodv,  235 
Rete  testis,  328 
Reticular  layer  of  derma,  341 

of  retina,  353 
Retina,  351 

structure  of,  352 
Retrabens  an  rem,  142 
Rhomboid  impression,  91 

ligament,  126 
Rliomboideus  major,  151 

minor,  151 
Rib,  parts  of,  81 
Ribs,  80 


INDEX. 


413 


Ribs,  develoimieut  of,  SI 

false,  80 

lloatiug,  80 

peculiar,  82 

true,  80 
Eidge,  interosseous,  110 

sui)racoudylar,  97 
Eight  auricle,  183 

ventricle,  183 
Einia  glottidis,  2UU 
Eiug,  abdominal,  external,  381 
internal,  381 

femoral,  384 
Eisorius,  145 
Eivinus,  ducts  of,  265 

notch  of,  365 
Eod-granules,  353 
Eods  of  Corti,  378 
Eolandic  angle,  238 

line,  238 
Eolando,  fissure  of,  225 

funiculus  of,  235 
Root  of  tooth,  260 
Rosenmiiller,  organ  of,  339 
Rostrum,  32 
Rotatores  spinae,  155 
Round  ligament  of  liver,  278 
of  uterus,  336 

window,  367 
Rugte  of  bladder,  320 

Sac,  lacrimal,  362 
Saccule,  .377 
Sacculus  laryngis,  299 
Sacral  arterv,  lateral,  205 
middle,  203 

canal,  76 

foramina,  75,  76 

groove,  76 

nerves,  256 

plexus,  253 
Sacro-coccygeal  articulation,  125 
Sacro-iliac  articulation,  124 
Sacro-sciatic  ligament,  125 

notch,  greater,  85 
Sacro-verti'bral  articulation,  124 
Sacrum,  74 

ccMiters  of  ossification  of,  77 

muscular  attachments  of,  77 
Sagittal  sutur(%  25,  .57 
Salivary  glands,  264 
Sal|iiniio-|iliarvngeal  fold,  268 
Salpin^o-iiliaryngeus,  371 
Santorini,  emissary  veins  of,  214 


Saphenous  opening,  170,  384 

veins,  218 
Sarcolemma,  140 
Sartorius,  170 
Scala  media,  377 

tympani,  375 

vestibuli,  375 
Scalenus  anticus,  149 

mcdius,  149 

posticus,  149 
Scaphoid  bone,  102 

fossa,  34 
Scapula,  91 

angles  of,  94 

borders  of,  94 

development  of,  94 

ligaments  of,  127 

muscular  attachments  of,  95 
Scarpa,  foramen  of,  47 
Scarpa's  triangle,  206 
Schachowa,  spiral  tubule  of,  313 
Schindylesis,  118 
Schlemm,  canal  of,  3.50 

inferior  ligament  of,  127 

internal  ligament  of,  127 
Schneiderian  membrane,  343 
Schwann,  white  substance  of,  222 
Sciatic  artery,  204 

nerves,  2.54 
Sclerotic,  347 

arteries  of,  347 
Scrotum,  .327 
Sebaceous  glands,  .342 
Second  nerve,  241 
Sella  turcica,  32 
Semicircular  canals,  .373 

membranous,  .376 
Semilunar  aortic  valves,  185 

bone,  102 

fibrocartilages,  135 

valves,  184 
Semimembranosus,  175 
Seminiferous  tubules,  328 
Semispinalis  colli,  154 

dorsi,  1.54 
Semitendinosus,  174 
Sense,  organs  of,  340 
Septum  crurale.  .385 

lucidum,  232 

nasal,  67 

j)ec(inif((rme,  325 
scroti,  ;)27 

tul)iP,  39,  61,:«i8 
Serratus  magnus,  161 


414 


INDEX. 


fcjcrratus  posticus,  inferior,  152 

superior,  152 
Sesamoid  bones,  20 
Seventh  nerve,  240 
Sharpey's  perforating  fibers,  19 
Sheath,  crural,  385 
Shin,  110 

Short  bones,  function  of,  21 
Shouhler-joiut,  127 

muscles  of,  ItJl 
Shrapnell's  membrane,  365 
Sigmoid  cavities,  99 

cavity,  100 

flexure,  275 

fossa,  30 

notch,  54,  56 
Sinus  circularis  iridis,  350 

coronary,  220 

definition  of,  214 

frontal,  25 

mediastino-costalis,  308 

mediastino-})hrenicus,  308 

I)hrenico-costalis,  308 

pocularis,  322,  331 

of  Valsalva,  184 
Sinuses  of  dura  mater,  214 

frontal,  23 
Sixth  nerve,  346 
Skin,  340 
Skull,  bones  of,  22 
Small  intestine,  272 
Smell,  organs  of,  343 
Soft  palate,  264 
Solar  plexus,  258 
Soleus,  176 
Solitary  glands,  274 
Sommering,  yellow  spot  of,  351 
Space  of  Tenon,  346 
Spaces  of  Fontana,  350 
Spermatic  arterv,  203,  329 

cord,  330 
Spheno-ethmoidal  recess,  67 
Sphenoid  bone,  31 

articulations  of,  34 
body  of,  31 

centers  of  ossification  of,  35 
greater  wings  of,  32 
lesser  wings  of,  34 
Sphenoidal  crest,  82 

fissure,  33,  34,  60,  64 

process,  51 

sinuses,  31 

turbinated  bone,  32 
Spheno-malar  suture,  64 


Spheno-maxillary  fissure,  33,  64,  68 

fossa,  69 
Spheno-palatine  foramen,  51,  67 

ganglion,  244 
Spheno-parietal  suture,  57 
Spheno-stai)liy linns,  371 
Sphincter  ani,  external,  386 
internal,  380 
tertius,  386 

pupilla?,  351 

vagina%  388,  390 

vesicae,  320 
Spinal  accessorv  nerve,  247 

cord,  239 

columns  of,  240 
fissures  of,  240 
membranes  of.  240 
ventricle  of,  241 

foramen,  72 

nerves,  248 

veins,  217 
Spinalis  colli,  154 

dorsi,  154 
Spine  of  ischium,  86 

of  scapula,  91 

of  tibia,  110 
Spinous  process  of  bones,  21 
of  sphenoid,  33 
of  vertebra,  71 
Spiral  canal  of  cochlea,  374 

groove,  95 

line  of  femur,  108 

tubercle  of  Schachowa,  313 

valve,  282 
Splanchnic  nerves,  258 
Spleen,  285 
Spleen -pulp,  286 
Splenic  arterv,  202,  286 

vein,  286 
Splcnius  capitis  et  colli,  152 
Spongj'  tissue  of  bone,  18 

urethra,  322 
S(|uamo-occipital  portion.  27 
S(|uamo-parietal  suture,  57 
S(|uamo-sphenoidal  suture,  57 
Squamous     portion     of     temporal 

bone,  35 
Stapedius.  369 
Stapes.  368 

Stars  of  Verhayen,  315 
Stellate  ligament,  123 

venous  plexuses,  315 
Stensen,  foramen  of,  47 
Steusen's  duct,  265 


INDEX. 


415 


Stensen's  duct,  openings  of,  264 
Steruo-clavicular  articulation,  126 
Sterno-cleido-niastoid  muscle,  146 
Sterno-hyoid  muscle,  14() 
Sterno-thyroid  muscle,  146 
Sternum,  SO 

ligaments  of,  124 
Stilling,  canal  of,  354 
Stirrup,  368 
Stomach,  270 

blood-  and  nerve-supply  of,  272 

coats  of,  271 

dimensions  and  position  of,  271 

relations  of,  271 
Straight  tubules,  314 
Stratum  mucosum,  341 
Striae  longitudiuales,  232 

medul lares,  234 
Stylo-glossus,  148 
Stylo-hyoid  muscle,  147 
Stvloid'process,  99,  100 
of  fibula,  112 
of  temporal,  39 
Stylo-mastoid  foramen,  39.  61 
Stylo-pharyugeus  muscle,  269 
Subanconeus,  163 
Subarachnoidean  space,  223,  240 
Subarcuate  fossa,  3rf,  61 
Subclavian  artery,  195 

surgical  anatomy,  212 

groove,  90 

vein,  216 
Subclavius,  161 
Subcostal  artery,  201 
Subcostales,  159 
Subcrural  bursa,  134 
Subcrureus,  172 
Subdural  space,  240 
Subcpitluilial  plexuses,  347 
Sublingual  fossa,  55 

gland,  2(i5 
Sublobular  vein,  280 
Submaxillary  fossa,  56 

ganglion,  245 

gland,  265 
8ul)s<;apular  angle,  91 

artery,  198 

fossa,  91 

nerves,  250 
Subscapnlaris,  161 
Sulci  (»f  ccrrbclium,  236 
Sulcus  spiralis,  377 

tubfe,  31 

tympanic  us,  365 


;  Superciliary  ridges,  23 
!  Sui)erior  curved  line,  28 
Supinator  brevis,  166 

longus,  165 
Supracondylar  ridges,  97 
Supraglenoid  tubercle,  94 
Supramarginal  gyrus,  227 
Supra-occipital  bone,  27 
Supra-orbital  arch,  23 
artery,  357 
foramen,  65 
notch,  23 
Suprapubic  ligament,  125 
Suprarenal  arterv,  inferior,  203 
middle,  202 
capsules,  288 
Suprascapular  artery,  196 
nerve,  250 
notch,  94 
Supraspinatus,  162 
Supraspinous  fossa,  91 
Supreme  curved  line,  28 
Suspensory  ligament  of  incus,  369 
of  lens,  355 
of  liver,  277,  278 
of  malleus,  368 
of  penis,  325 
of  spleen,  285 
Sustentaculum  lienis,  285 
Sutura  dentata,  118 
harmonia,  118 
limbosa,  118 
notha,  118 
serrata,  118 
squamosa,  118 
vera,  117 
Suture,  basi-sphenoidal,  57 
coronal,  57 
ethmo-sphenoidal,  64 
fronto-malar,  64 
fronto-parietal,  57 
fronto-si)hcnoidal,  64 
interparietal,  57 
lacrimo-ethmoidal,  64 
lambdoid,  57 
malo-maxillary,  64 
masto-occipital,  57 
masto-parit'tal,  57 
occipito-parictal,  57 
l»aIato-ma.\illary,  64 
|)etro-occipital,  57 
ptitro-sphenoiiJal,  57 
sagittal,  57 
of  the  skull,  57 


416 


INDEX. 


Suture,  spbciKi-niular,  (j4 

spheuo-purietal,  57 

squauKJ-parietal,  57 

squaiuo-sjiliL-uoidal,  57 

transverse,  57 
Sweat-glauds,  342 
Sylviau  line,  '2'SU 

point,  2'.i[) 
Sylvius,  fissure  of,  225 
Sympathetic  nerve,  256 
Symphysis  of  mandible,  55 

of  pubes,  87 
Synarthroses,  117 
Synchondrosis,  117 
Syndesmosis,  117 
Synostosis,  117 

Tactile  corpuscles,  341 
Taenia  hippocampi,  232 
semieircularis,  230 
Tapetum  fibrosum,  349 
Tarsal  artery,  210 
bones,  113 
cartilages,  360 
joints,  137 
ligaments,  360 
Tarso-metatarsal  articulation,  139 
Tarsus,  svnovial  sacs  of,  139 
Taste-buds,  343 
Taste-hair,  343 
Taste,  organs  of,  342 
Tears,  361 
Teeth,  260 

blood-  and  nerve-supply  of,  2G2 
development  of,  263 
structure  of,  261 
varieties  of,  261 
Tegmen  tympani,  38,  60,  366 
Temiioral  artery,  superficial,  192 
bone,  35 

articulations  of,  40 
centersof  ossification  of,  40 
mastoid  portion,  3(5 
muscular    attaclnnents   of, 

40 
petrous  portion,  37 
squamous  portion,  35 
fossa.  67 
muscle,  145 
ridges.  26,  68 
inferior,  24 
Temporary  teeth,  260 

a])]iearance  of,  262 
Temporo-malar  canals,  49 


Temporo  -  maxillary     articulation, 

122 
Temporo-sphenoidal  lobe,  226 
Tendo  oculi,  3(50 
Tendon,  conjoined,  156 
Tendons,  141 
Tenon,  capsule  of,  345 

s])ace  of,  346 
Tensor  fasciae  femoris,  170 

palati,  148 

tarsi,  142 

tympani,  369 
Tenth  nerve,  247 
Tentorium  cerebelli,  223 
Teres  major,  162 

minor,  162 
Testes,  327 

descent  of,  331 

structure  of,  328 

vessels  of,  329 
Testicles,  327 

nerves  of,  330 
Thalamencephalon,  224 
Third  nerve,  242 

ventricle,  233 
Thoracic  aorta,  200 

surgical  anatomy,  212 

artery,  alar,  198 
long,  198 
superior,  197 

duct,  221 

nerves,  2.52 
Thorax,  measurements  of,  310 

muscles,  159 

structure,  form,  and  boundaries 
of,  78 

structures  contained  in,  80 

veins  of,  217 
Thymus  gland,  287 

blood-suj)ply  of,  288 
Thyro-arytenoideus,  'SOB 
Tliyro-epiuh)ttie  ligament,  297 
Thyro-epiglottideus,  300 
Tliyro-glossal  duct,  266 
Tliyro-hyoid  muscle,  146 
Thyroid  artery,  superior,  191 

axis,  196 

cartilage,  195 

foramen,  84 

gland,  286 

arteries  of,  287 
nerves  of,  287 

structure  of,  288 

veins  of.  287 


INDEX. 


417 


Thyroidea  ima,  190 
Tibia,  110 

development  of,  112 

muscular  attachments  of,  112 
Tibial  artery,  anterior,  209 
posterior,  210 

nerve,  anterior,  255 
posterior,  255 
Tibialis  anticus,  175 

posticus,  177 
Tibio-fibular  articulation,  136 
Tomes'  fibers,  262 
Tongue,  265 

blood-supply  of,  266 

nerve-supply  of,  266 
Tonsil,  264 

lingual,  266 

pharyngeal,  268 

tubal,  268 
Tooth,  parts  of,  260 
Torus  transversus,  28 
Trachea,  301 

blood-  and  nerve-supply  of,  303 

relations  of,  in  neck,  302 
in  thorax,  302 
Trachealis  muscle,  301 
Trachelo-mastoid  muscle,  154 
Tractus  spiralis  foraminulentus,  380 
Tragi cus,  364 
Tragus,  363 
Transversalis,  157 

colli,  153,  196 
Transverse  colon,  275 

disk,  140 

fissure,  226 

processes  of  vertebra,  71 

suture,  57 
Transversus  auriculae,  364 

perinei,  387 
Trapezium,  104 
Trapezius,  158 
Trapezftid  bone,  104 

ligaTn<'nt,  127 
Triangular  ligament,  389 

notch,  34 
Triangularis  sterni,  159 
Tric('j)s  (!xt(;nsor  cubiti,  163 
Triciisi.id  valve,  1H2,  184 
Trifacial  nerve,  243 
Trigeminus,  243 
Trigonuni  acustici,  234 

habcmbr',  233 

hypoglossi,  234 

vagi,  234 

27 


j  Trigonum  vesicae,  320 
Triticeo-glossus,  300 
Trochanters,  21 
I  of  femur,  108 

;  Trochlea  of  femur,  109 
Trochlear  fossa,  24 
nerve,  242 

surface  of  humerus,  97 
Trochoides,  118 
True  pelvis,  88 
ribs,  80 
vertebrae,  69 
Tubal  tonsils,  268 
Tube,  Eustachian,  371 
Tuber  annulare,  235 
of  pons,  229 
cinereura,  229 
valvulae,  237 
Tubercle,  conoid,  90 
of  Darwin,  364 
deltoid,  90 
Lisfranc's,  82 
of  Lower,  183 
supraglenoid,  94 
Tubercles  of  bones,  21 
Tuberosities  of  bones,  21 
of  humerus,  95 
of  tibia,  110 
Tuberosity  of  ischium,  86 
of  radius,  100 
of  rib,  81 
Tubular  membrane,  222 
Tubuli  lactiferi,  339 

uriniferi,  313 
Tunica  albuginea  testis,  327 
Ruyschiana,  349 
vaginalis,  327 
oculi,  345 
l)ropria,  327 
reflexa,  327 
testis,  331 
vasculosa,  327 
Turbinated  bones,  42 
inferior,  52 
crest,  inferior,  46,  251 
superior,  46 
Tutamina  oculi,  359 
Twelfth  nerve,  24H 
Tympanic  artery,  194,  370 
n«'rve,  370 
plexus,  370 
sjiines,  365 
Tympanum,  365,  366 
ait(!ries  of,  369 


418 


INDEX. 


Tympanum,  muscles  of,  369 

nerves  of,  370 
Tyson's  glands,  326 

Ulna,  97 

development  of.  99 

muscular  attachments  of,  100 
Ulnar  artery,  199 

nerve,  251 
Umbilical  fissure,  278 

region,  291 
Umbo,  .365 
Unciform  bone,  104 

process  of  ethmoid,  41 
Uncinate  gyrus,  226 
Ungual  processes,  106 
Upper  extremity,  veins  of,  215 
Urachus,  319 
Ureter,  317 

muscles  of,  320 
Urethra,  female,  323 

male.  321 

structure  of,  323 
Urinary  organs,  312 
Urogenital  space.  332 
Uterine  arterv,  204,  336 
Uterus.  3.34 

blood-vessels  of,  336 

ligaments  of,  3.35 

masculinus,  322 

nerves  of,  337 

structure  of,  336 
Utricle,  376 
Uvea,  350 
Uvula  of  cerebellum,  237 

vesicfe,  321 

Vagina,  333 
Vaginal  orifice,  332 

process,  32 

of  temporal  bone,  39 
Vagus  nerve,  247 
Valsalva,  sinus  of,  184 
Valve,  aortic,  182 

of  Bauhin,  273,  275 

coronary,  183 

Eustachian,  183 

of  Hasner,  362 

of  Ileister,  282 

ileo-cecal,  273,  275 

mitral,  182,  185 

pulmonary,  182 

semilunar,  184 

spiral,  282 


Valve,  tricuspid,  182,  184 

of  Vieussens,  2.33 
Valves,  pulmonary  semilunar,  184 

semilunar  aortic,  185 
Valvula?  conniventes,  273 
Vas  abcrrans,  329 

deferens,  329 
Vasa  etferentia,  .328 

nervorum.  222 

vasorum,  187 

vesta,  328 
Vascular  system,  181 
Vastus  externus.  171 

internus,  172 
Vein,  axillary,  215 

azygos,  217 

emulgent,  316 

iliac,  common,  219 
internal,  219 

jugular,  215 

portal,  279 

renal,  316 

saphenous,  218 

splenic,  286 

subclavian.  216 

subglobular,  280 

vertebral,  215 
Veins,  213 

of  auricle,  364 

of  choroid.  349 

dorsi-spinal,  217 

of  eye,  358 

of  head,  214 
■  of  heart,  220 

hepatic,  280 

interlobular,  280 

of  iris,  351 

of  kidney,  315 

of  larynx,  .300 

of  lower  extremity,  218 

medulli-spinal,  218 

meningo-rachidian,  218 

of  neck,  214 

pulmonary,  220 

spinal,  217 

of  testicle,  330 

of  thorax,  217 

of  upper  extremity,  215 
Vena  cava,  inferior,  219 

superior,  216 
Vena?  basis  vertebrarum,  218 

comites,  214 

innominatae,  216 

interlobulares,  316 


INDEX. 


419 


Venae  proprife  venales,  316 

rectse,  316 

vorticosre,  349 
Ventrifde  of  cord,  241 

fifth,  233 

fourth,  234 

of  larvnx,  299 

left.  185 

risht,  183 

third,  233 
Ventricles  of  brain,  231 

lateral,  231 
Vermiform  fossa,  30 

processes,  236 
Vertebra,  articular  processes  of,  71 

body  of,  70 

development  of,  73 

lamina;  of,  71 

pedicles  of,  70 

prominens,  73 

spinous  processes  of,  71 

transverse  processes  of,  71 
Vertebrae,  false,  69 

true,  69 
Vertebral  artery,  196 

articulations,  119 

column,  69 

line,  .310 

muscles,  149 

notches,  70 

vein,  215 
Vertical  plate  of  palate  bone,  51 
Verumontanum,  322 
Vesical  arteries,  204 
Vesico-uterine  lifjament,  335 
Vesiculae  seminales,  .330 
Vestibular  nerve,  380 
Vestibule  of  labyrinth,  .372 

of  vagina,  3.32 


Vidian  canal,  34 

nerve,  345 
Viscera,  abdominal,  289 
Viscus,  definition,  259 
Vitelline  membrane,  338 
Vitellus,  .3.38 
Vitreous  body,  354 

humor,  .346 
Vocal  cords,  298 
Vomer,  .53 
Vulva,  331 

Wharton's  duct,  265 

openings  of,  264 
White  substance  of  Schwann,  222 
Willis,  circle  of,  194 
Wings  of  sphenoid,  greater,  32 
lesser,  34 

of  vomer,  53 
Winslow,  foramen  of.  293 
Wisdom  teeth,  261 
Worm,  236 
Wormian  bones,  20 
Wrisberg,  cartilages  of,  297 

ligament  of,  135 
Wrist-joint,  130 

Y-LIGAMEXT,  1.32 

Yellow  maiTow,  19 

spot  of  Sommering,  351 

ZiXN,  zonula  of,  .355 
Zona  arcuata,  378 

pellucida.  338 

radiata.  338 
Zonula  of  Zinn,  .355 
Zygomatic  fossa,  68 

process,  .35,  49 
Zygomaticus  minor,  144 


Catalogue    the    Medical     Publications 


OF 


W.   B.  SAUNDERS   &   COMPANY 

PHILADELPHIA       .j8        jt        .jt        .ji        .Jt  LONDON 

925  Walnut  Street     ji        .Jt        .ji        .Jt        .jt    161  Strand,  VV.  C. 

Arranged  Alphabetically  and  Classified    under   Subjects 
See  page  18  for  a  List  of  Contents  classified  according  to  subjects 


THE  books  advertised  in  this  Catalogue  as  being  send  cy  subscription  asc  usuaiiy  to  be 
obtained  from  travelling  solicitors,  but  they  will  be  sent  direct  from  the  ofiBce  oi  pub- 
lication (^charges  of  shipment  prepaid)  upon  receipt  of  the  prices  given.     All  the  other 
books  advertised  are  commonly  for  sale  by  booksellers  in  all  parts  of  the  United  States;  but 
books  will  be  sent  to  any  address,  carriage  prepaid,  on  receipt  of  the  published  price. 

Money  may  be  sent  at  the  risk  of  the  publisher  in  either  of  the  following  ways  :  A  postal 
money  order,  an  express  money  order,  a  bank  check,  and  in  a  registered  letter.  Money 
sent  in  any  other  way  is  at  the  risk  of    the  sender. 

SPECIAL  To  physicians  of  approved  credit  books  will  be  sent,  post-paid,  on  the  following 
OFFER  terms  :  $5.00  cash  upon  delivery  of  books,  and  monthly  payments  of  555.00  there- 
after until  full  amount  is  paid.     Any  one  or  two  volumes  will  be  sent  on  thirty  days'  time 

to  those  who  do  not  care  to  make  a  larger  purchase. 


AN  AMERICAN  TEXT=BOOK  OF  APPLIED  THERAPEUTICS. 

Edited  by  James  C.  Wilson,  M.  D.,  Professor  of  Practice  of  Medi.ir.e  ar.d 
of  Clinical  Medicine,  Jefferson  Medical  College,  Philadelphia.  Handsome 
imperial  octavo  volume  of  1326  pages.  Illustrated.  Cloth,  $7.00  net ; 
Sheep  or  Half  Morocco,  $8.00  net.     Sold  by  Subscription. 

AN  AMERICAN   TE.\T=BOOK  OF   THE    DISEASES  OF  CHIL= 
DREN.     Second  Edition,  Revised. 

Edited  by  Louis  Starr.  M.  D.,  Consulting  Pediatrist  to  the  Maternity  Hos- 
pital, etc';  assisted  by  THOMPSON  S.  Westcott.  M.  D.,  .Attending  Physi- 
cian to  the  Dispensary  for  Diseases  of  Children,  Hospital  of  the  University 
of  Pennsylvania.  Handsome  imperial  octavo  volume  of  1244  pages,  pro- 
fusely illustrated.  Cloth,  $7.00  net ;  Sheep  or  Half  Morocco,  $8.00  net. 
Sold  by  Subscription. 

AN  AMERICAN   TEXT=BOOK  OF    DISEASES  OF   THE   EYE, 
EAR,  NOSE,  AND  THROAT. 

Edited  bv  G.  E.  DE  SCHWEIMTZ,  M.  D.  Professor  of  Ophthalmology. 
Jefferson 'Medical  College,  Philadelphia;  and  B.  .ALE.VANDER  Randall. 
M.  D..  Clinical  Professor  of  Diseases  of  the  Elir,  University  of  Pennsylvania. 
Imperial  octavo,  1251  pages;  706  illustrations,  59  of  them  in  colors.  Cloth, 
^7,00  net ;  Sheep  or  Ha.f  .Morocco,  $3.oo  net.     Sold  by  Subscription. 


MEDICAL    PUBLICATIONS 


AN    AMERICAN    TEXT=BOOK    OF    QENITO=URINARY     AND 

SKIN  DISEASES. 

Edited  by  L.  Boi.'lON  Bangs,  M.  D.,  Professor  of  Gcnito-Urinury  ?urgery, 
University  and  Bellevue  Hospital  Medical  College,  New  York  ;  and  W.  A. 
Hardaway,  M.  D.,  Professor  of  Diseases  of  the  Skin,  Missouri  Medical 
College.  Imperial  octavo  volume  of  1229  pages,  with  300  engravings  and 
20  full-page  colored  plates.  Cloth,  $7.00  net ;  Sheep  or  Half  Morocco, 
^8.00  net.     Sold  by  Subscription. 

AN    AMERICAN   TEXT=BOOK   OF   GYNECOLOGY,   MEDICAL 
AND  SURGICAL.    Second  Edition,  Revised. 

Edited  by  j.  M.  Baldv,  M.  D.,  Professor  of  Gynecology,  Philadelphia 
Polyclinic,  etc.  Handsome  imperial  octavo  volume  of  718  pages;  341  illus- 
trations in  the  text,  and  38  colored  and  half-tone  plates.  Cloth,  ^6.00  net ; 
Sheep  or  Half  Morocco,  $7.00  net.     Sold  by  Subscription. 

AN    AMERICAN    TEXT=BOOK   OF    LEGAL    MEDICINE    AND 

TOXICOLOGY. 

Edited  by  Frederick  Peterson,  M.  D.,  Chief  of  Clinic,  Nervous  Depart- 
ment, College  of  Physicians  and  Surgeons,  New  York  ;  and  Walter  S. 
Haines,  M.  D.,  Professor  of  Chemistry,  Pharmacy,  and  Toxicology,  Rush 
Medical  College,  Chicago.     In  Preparation. 

AN  AMERICAN  TEXT=BOOK  OF  OBSTETRICS. 

Edited  by  RICHARD  C.  NoRRis,  M.  D  ;  Art  Editor,  Robert  L.  Dickinson, 
M.  D.  Handsome  imperial  octavo  volume  of  1014  pages  ;  nearly  900  beau- 
tiful colored  and  half-tone  illustrations.  Cloth,  ^7.00  net ;  Sheep  or  Half 
Morocco,  $8.00  net.     Sold  by  Subscription. 

AN  AMERICAN  TEXT=BOOK  OF  PATHOLOGY. 

Edited  by  LUDWIG  Hektoen,  M.  D.,  Professor  of  Pathology  in  Rush 
Medical  College,  Chicago  ;  and  David  Riesman,  M.  D.,  Demonstrator  of 
Pathologic  Histology  in  the  University  of  Pennsylvania.  Handsome  im- 
perial octavo,  over  1200  pages,  profusely  illustrated.     By  Subscription. 

AN  AMERICAN  TEXT=BOOK  OF  PHYSIOLOGY.     Second  Edi= 
tion.  Revised,  in  Two  Volumes. 

Edited  by  WILLIAM  H.  HoWELL,  Ph.  D.,  M.  D.,  Professor  of  Physiology, 
Johns  Hopkins  University,  Baltimore,  Md.  Two  royal  octavo  volumes  of 
about  600  pages  each.  Fully  illustrated.  Per  volume:  Cloth,  ^3.00  net; 
Sheep  or  Haff  Morocco,  $3.75  net. 

AN  AMERICAN  TEXT=BOOK  OF  SURGERY.    Third  Edition. 

Edited  by  William  W.  Keen.  M.  D.,  LL.D.,  F.  R.  C.  S.  (Hon.);  and 
y.  William  White,  M.  D.,  Ph.  D.  Handsome  octavo  volume  of  1250 
pages  ;  496  wood-cuts  and  37  colored  and  half-tone  plates.  Thoroughly 
revised  and  enlarged,  with  a  section  devoted  to  "The  Use  of  the  Ront- 
gen  Ravs  in  Surgery."  Cloth,  $7.00  net;  Sheep  or  Half  Morocco, 
fi8.oo  net. 


OF  W.  B.   SAUNDERS  6-  CO. 


THE  NEW  STANDARD  THE   NEW   STANDARD 

THE    AMERICAN    ILLUSTRATED    MEDICAL    DICTIONARY. 
Second  Edition,  Revised. 

For  Practitioners  and  Students.  A  Complete  Dictionary  of  the  Terms  used 
in  Medicine,  Surgery,  Dentistry,  Pharmacy,  Chemistry,  and  the  kindred 
branches,  including  much  collateral  information  of  an  encyclopedic  character, 
together  with  new  and  elaborate  tables  of  Arteries,  Muscles,  Nerves,  Veins, 
etc.  ;  of  Bacilli,  Bacteria,  Micrococci,  Streptococci  ;  Eponymic  Tables  of 
Diseases,  Operations,  Signs  and  Symptoms,  Stains,  Tests,  Methods  of  Treat- 
ment, etc.,  etc.  By  W.  A.  Newman  Dorland,  A.  M.,  M.  D.,  Editor 
of  the  "  American  Pocket  Medical  Dictionary."  Handsome  large  octavo, 
nearly  8oo  pages,  bound  in  full  flexible  leather.  Price,  ^4.50 net;  with 
thumb  index,  $5.00  net. 

Gives  a  Maximum  Amount  of  Matter  in  a  Minimum  Space  and  at  the  Lowest 

Possible  Cost. 

This  Revised  Edition  contains  all  the  Latest  Terms. 

"  I  must  acknowledge  my  astonishment  at  seeing  how  much  he  has  condensed  within 
relatively  small  space.  I  find  nothing  to  criticise,  very  much  to  commend,  and  was  in- 
terested in  finding  some  of  the  new  words  which  are  not  in  other  recent  dictionaries." — 
RoswELL  Park,  Professor  of  Principles  and  Practice  of  Surgery  and  Clinical  Surgery, 
University  of  Buffalo. 

"  I  congratulate  you  upon  giving  to  the  profession  a  dictionary  so  compact  in  its  structure, 
and  so  replete  with  information  required  by  the  busy  practitioner  and  student.  It  is  a 
necessity  as  well  as  an  informed  companion  to  every  doctor.  It  should  be  upon  the  desk 
of  every  practitioner  and  student  of  medicine." — John  B.  Murphy,  Professor  of  Surgery 
and  Clinical  Surgery,  Northwestern  University  Medical  School,  Chicago. 

THE   AMERICAN    POCKET    MEDICAL    DICTIONARY.    Third 
Edition,  Revised. 

Edited  by  W.  A.  NEWMAN  DoRLAND.,  M.  D.,  Assistant  Obstetrician  to  the 
Hospital  of  the  University  of  Pennsylvania;  Fellow  of  the  American  Acad- 
emy (jf  Medicine.  Containing  the  pronunciation  and  definition  of  the  prin- 
cipal words  used  in  medicine  and  kindred  sciences,  with  64  extensive  tables. 
Handsomely  bound  in  flexible  leather,  with  gold  edges.  Price  $1.00  net; 
with  thumb  index,  $1.25  net. 

THE  AMERICAN  YEAR=BOOK  OF  MEDICINE  AND  SURGERY. 

A  Yearly  Digest  of  Scientific  Progress  and  Authoritative  Opinion  in  all 
branches  of  Medicine  and  Surgery,  drawn  from  journals,  monographs,  and 
text-books  of  the  leading  American  and  Foreign  authors  and  investigators. 
Arranged  with  editorial  comments,  by  eminent  American  specialists,  under 
the  editorial  charge  of  George  M.  Gould,  M.  D.  Year-Book  of  1901 
in  two  volumes — Vol.  I.  including  Cieneral  Medicine  ;  Vol.  IL,  General  Sur- 
gery. Per  volume  :  Cloth,  $3.00  net ;  Half  Morocco,  $3.75  net.  Sold  by  Sub- 
scription. 

ABBOTT  ON   TRANSMISSIBLE  DISEASES.     Second   Edition, 
Revised. 

The  Hygiene  (jf  Transmissible  Diseases:  their  Causation,  Modesof  Dissem- 
ination, and  .VIetiiods  of  IVevention.  By  A.  C.  AhhoTI',  M.  D.,  I'rofcssor 
of  Hygiene  and  Fiacteriology,  University  of  Pennsylvania.  Octavo,  351 
pages,  with  numt^rous  illustrations.     Cloth,  ^2.50  net. 


MEDICAL   rURLlCA  TlUNS 


ANDERS'  PRACTICE  OF  MEDICINE.     Fifth  Revised  Edition. 

A  Text-Book  of  the  Practice  of  Medicine.  By  J  AMES  M.  ANDERS,  M.  D.. 
Ph.  D.,  LL.  D..  Professor  of  the  Practice  of  Medicine  and  of  Clinical  Med- 
icine, Medico-Chirurgical  College,  Philadelpliia.  Handsome  octavo  volume 
of  1292  pages,  fully  illustrated.  Cloth,  $5.50  net;  Sheep  or  Half  Morocco, 
$6.50  net. 

BASTIN'S  BOTANY. 

Laboratory  Exercises  in  Botany.  By  Edson  S.  Bastin,  M.  A.,  late  Pro- 
fessor of  Materia  Medica  and  Botany,  Philadelphia  College  of  Pharmacy. 
Octavo,  536  pages,  with  87  plates.     Cloth,  ^2.00  net. 

BECK  ON  FRACTURES. 

Fractures.  By  CARL  BECK,  M.  D.,  Surgeon  to  St.  Mark's  Hospital  and 
the  New  York  German  Poliklinik,  etc.  With  an  appendix  on  the  Practical 
Use  of  the  Rontgen  Rays.     335  pages,  170  illustrations.     Cloth,  $3.50  net. 

BECK'S  SURGICAL   ASEPSIS. 

A  Manual  of  Surgical  Asepsis.  By  Carl  Beck,  M.  D.,  Surgeon  to  St. 
Mark's  Hospital  and  the  New  York  German  Poliklinik,  etc.  306  pages;  65 
text-illustrations  and  12  full-page  plates.     Cloth,  $1.25  net. 

BOISLINIERE'S    OBSTETRIC    ACCIDENTS,    EMERGENCIES, 

AND  OPERATIONS. 

Obstetric  Accidents,  Emergencies,  and  Operations.  By  L.  Ch.  BOISLIN- 
IERE,  M.D.,  late  Emeritus  Professor  of  Obstetrics,  St.  Louis  Medical  Col- 
lege.    381  pages,  handsomely  illustrated.     Cloth,  ^2.00  net. 

BOHM,   DAVIDOFF,   AND   HUBER'S   HISTOLOGY. 

A  Text-Book  of  Human  Histology.  Including  Microscopic  Technic.  By 
Dr.  a.  a.  Bohm  and  Dr.  M.  von  Davidoff,  of  Munich,  and  G.  Carl 
Huber,  M.  D.,  Junior  Professor  of  Anatomy  and  Director  of  Histological 
Laboratory,  University  of  Michigan.  Handsome  octavo  of  501  pages,  with 
351  beautiful  original  illustrations.     Cloth,  $3.50  net. 

BUTLER'S      MATERIA      MEDICA,     THERAPEUTICS,     AND 
PHARMACOLOGY.    Third  Edition,  Revised. 

A  Text-Book  of  Materia  Medica,  Therapeutics,  and  Pharmacology.  By 
George  F.  Butler,  Ph.G.,  M.  D.,  Professor  of  Materia  Medica  and  of 
Chnical  Medicine,  College  of  Physicians  and  Surgeons,  Chicago.  Octavo, 
874  pages,  illustrated.    Cloth,  $4.00  net ;  Sheep  or  Half  Morocco,  fc.oo  net. 

CERNA    ON    THE    NEWER     REMEDIES.       Second     Edition, 
Revised. 

Notes  on  the  Newer  Remedies,  their  Therapeutic  Applications  and  Modes 
of  Administration.  By  David  Cerna,  M.  D.,  Ph.  D.,  Demonstrator  of 
Physiology,  Medical  Department,  University  of  Texas.  Rewritten  and 
greatly  enlarged.     Post-octavo,  253  pages.     Cloth,  $1.00  net. 


OF   W.  B.  SAUNDERS  &-    CO. 


CHAPIN  ON  INSANITY. 

A  Compendium  of  Insanity.  By  JOHN  B.  Chapin,  M.  D.,  LL.D.,  Phy- 
sician-in-Chief,  Pennsylvania  Hospital  for  the  Insane;  Honorary  Member 
of  the  Medico-Psychological  Society  of  Great  Britain,  of  the  Society  of 
Mental  Medicine  of  Belgium,  etc.  i2mo,  234  pages,  illustrated.  Cloth, 
^1.25  net. 

CHAPMAN'S  MEDICAL  JURISPRUDENCE  AND  TOXICOLOGY. 
Second  Edition,  Revised. 

Medical  Jurisprudence  and  Toxicology.  By  Henry  C.  Chapman,  M.  D., 
Professor  of  Institutes  of  Medicine  and  Medical  Jurisprudence,  Jefferson 
Medical  College  of  Philadelphia.  254  pages,  with  55  illustrations  and  3 
full-page  plates  in  colors.     Cloth,  $1,50  net. 

CHURCH  AND  PETERSON'S  NERVOUS  AND  MENTAL  D1S= 
EASES.     Third  Edition,  Revised  and  Enlarged. 

Nervous  and  Mental  Diseases.  By  ARCHIBALD  CHURCH,  M.  D.,  Pro- 
fessor of  Nervous  and  Mental  Diseases,  and  Head  of  the  Neurological 
Department,  Northwestern  University  Medical  School,  Chicago ;  and 
Frederick  Peterson,  M.  D.,  Chief  of  Clinic,  Nervous  Department,  Col- 
lege of  Physicians  and  Surgeons,  New  York.  Handsome  octavo  volume  of 
875  pages,  profusely  illustrated.  Cloth,  $5.00  net ;  Sheep  or  Half  Morocco. 
^6.00  net. 

CLARKSON'S  HISTOLOGY. 

A  Text-Book  of  Histology,  Descriptive  and  Practical.  By  Arthur  Clark- 
SON,  M.  B.,  C.  M.  Edin.,  formerly  Demonstrator  of  Physiology  in  the  Owen's 
College,  Manchester  ;  late  Demonstrator  of  Physiology  in  Yorkshire  College, 
Leeds.  Large  octavo,  554  pages  ;  22  engravings  and  174  beautifully  colored 
original  illustrations.     Cloth,  ^4.00  net. 

CORWIN'S  PHYSICAL  DIAGNOSIS.    Third  Edition,  Revised. 

Essentials  of  Physical  Diagnosis  of  the  Thorax.  By  ARTHUR  M.  CORWIN, 
A.  M.,  M.  D.,  Instructor  in  Physical  Diagnosis  in  Rush  Medical  College, 
Chicago.     219  pages,  illustrated.     Cloth,  ^1.25  net. 

CROOKSHANK'S   BACTERIOLOGY.     Fourth  Edition,  Revised. 

A  Text-Book  of  Bacteriology.  By  Edgar  M.  Crookshank,  M.  B.,  Pro- 
fessor of  Comparative  Pathology  and  Bacteriology,  King's  College,  London. 
Octavo,  700  pages,  273  engravings  and  22  original  colored  plates.  Cloth, 
$6.50  net ;   Half  Morocco,  $7.50  net. 

DACOSTA'S  SURGERY.    Third  Edition,  Revised. 

Modern  Surgery,  Cencral  and  0|icrativc.  By  JoHN  CHALMERS  DaCoSTA, 
M.  D.,  Professor  of  l^rincipk-s  of  Surgery  and  Clinical  Surgery,  Jefferson 
Medical  College,  Philadelphia  ;  Surgeon  to  the  Philadelphia  Hospital,  etc. 
Handsome  octavo  volume  of  11 17  pages,  profusely  illustrated.  Cloth,  ^5.00 
net;  Sheep  or  Half  Morocco,  ^'^•oo  net. 

Enlarged  by  over  200  Pages,  with  more  than  100  New  Illus- 
trations. 


MEDIC  A  L    PUBL ICA  TIOXS 


DAVIS'S  OBSTETRIC  NURSING. 

Obstetric  and  Gynecologic  Nursing.  By  Edward  P.  Davis,  A.  M.,  M.  D., 
Professor  of  Obstetrics  in  Jefferson  Medical  College  and  the  Philadelphia 
Polyclinic ;  Obstetrician  and  Gynecologist  to  the  Philadelphia  Hospital. 
i2mo  volume  of  400  pages,  fully  illustrated.     Crushed  buckram,  $1.75  net. 

DE   SCHWEINITZ  ON  DISEASES  OF  THE   EYE.     Third   Edi- 
tion, Revised. 

Diseases  of  the  Eye.  A  Handbook  of  Ophthalmic  Practice.  By  G.  E. 
DE  SCHWEINITZ,  M.  D.,  Professor  of  Ophthalmology,  Jefferson  Medical 
College,  Philadelpliia,  etc.  Handsome  royal  octavo  volume  of  696  pages  ; 
256  fine  illustrations  and  2  chromo-lithographic  plates.  Cloth,  $4.00  net ; 
Sheep  or  Half  Morocco,  $5.00  net. 

DORLAND'S  DICTIONARIES. 

[See  American  Illustrated  Medical  Dictionary  and  American 
Pocket  Atedical  Dictionary  on  page  3.] 

DORLAND'S    OBSTETRICS.      Second     Edition,    Revised    and 
Greatly  Enlarged. 

Modern  Obstetrics.  By  W.  A.  NEWMAN  DORL.A.ND,  M.  D.,  Assistant 
Demonstrator  of  Obstetrics,  University  of  Pennsylvania  ;  Associate  in  Gyne- 
cology, Philadelphia  Polyclinic.  Octavo  volume  of  797  pages,  with  201 
illustrations.     Cloth,  54.00  net. 

EICHHORST'S  PRACTICE  OF  MEDICINE. 

A  Text-Book  of  the  Practice  of  Medicine.  By  Dr.  Herman  Eichhorst, 
Professor  of  Special  Pathology  and  Therapeutics  and  Director  of  the  Medi- 
cal Clinic,  University  of  Zurich.  Translated  and  edited  by  AUGUSTUS  A. 
ESHNER,  M.  D.,  Professor  of  Clinical  Medicine,  Philadelphia  Polyclinic. 
Two  royal  octavo  volumes,  600  pages  each,  150  illustrations.  Per  set : 
Cloth,  S6.00  net;  Sheep  or  Half  Morocco,  $7.50  net. 

FRIEDRICH  AND  CURTIS  ON  THE  NOSE,  THROAT,  AND 
EAR. 

Rhinolog)',  Laryngology,  and  Otolog\\  and  their  Significance  in  General 
Medicine.  By  Dr.  E.  P.  Friedrich,  of  Leipzig.  Edited  by  H.  HoLBROOK 
Curtis,  M.  D.,  Consulting  Surgeon  to  the  New  York  Nose  and  Throat  Hos- 
pital.    Octavo,  348  pages.     Cloth,  $2.50  net. 

FROTHINGHAM'S  GUIDE  FOR  THE  BACTERIOLOGIST. 

Laboraton,'  Guide  for  the  Bacteriologist.  By  Langdon  Frothingham, 
M.  D.  v..  Assistant  in  Bacteriology  and  Veterinary  Science,  Sheffield  Scien- 
tific School,  Yale  University.     Illustrated.     Cloth,  75  cts.  net. 

GARRIGUES'    DISEASES    OF    WOMEN.     Third   Edition,   Re= 

vised. 

Diseases  of  Women.  By  Henry  J.  Garrigues,  A.  M.,  M.  D.,  Gynecolo- 
gist to  St.  Mark's  Hospital  and  to  the  German  Dispensary,  New  York  City. 
Octavo,  756  pages,  with  367  engravings  and  colored  plates.  Cloth,  ^4.50 
net;  Sheep  or  Half  Morocco,  $5.50  net. 


OF  IV.  B.   SAUNDERS  <^  CO. 


GOULD  AND  PYLE'S  CURIOSITIES  OF  MEDICINE. 

Anomalies  and  Curios  ties  of  Medicine.  By  Geokge  M.  GoL'LD,  M.  D., 
and  Walter  L.  Pyle,  M.  D.  An  encyclopedic  collection  of  rare  and  ex- 
traordinary cases  and  of  the  most  striking  instances  of  abnormality  in  all 
branches  of  Medicine  and  Surgery,  derived  from  an  exhaustive  research  of 
medical  literature  from  its  origin  to  the  present  day,  abstracted,  classified, 
annotated,  and  indexed.  Handsome  octavo  volume  of  968  pages  ;  295  en- 
gravings and  12  full-page  plates.  Popular  Edition.  Cloth,  $3.00  net ;  Sheep 
or  Half  Morocco,  S4.00  net. 

GRAFSTROM'S  MECHANO=THERAPY. 

A  Text-Book  of  Mechano-Therapy  (Massage  and  Medical  Gymnastics). 
By  Axel  V.  Grafstrom,  B.  Sc,  M.  D.,  late  House  Physician.  City  Hos- 
pital, Blackweli's  Island,  New  York.  i2mo,  139  pages,  illustrated.  Cloth, 
^i.oo  net. 

GRIFFITH  ON  THE  BABY.     Second  Edition,  Revised. 

The  Care  of  the  Baby.  By  J.  P.  Crozer  GRIFFITH,  M.  D.,  Clinical  Pro- 
fessor of  Diseases  of  Children,  University  of  Pennsylvania  ;  Physician  to  the 
Children's  Hospital,  Philadelphia,  etc.  i2mo,  404  pages,  67  illustrations 
and  5  plates.     Cloth,  $1.50  net. 

GRIFFITH'S  WEIGHT  CHART. 

Infant's  Weight  Chart.  Designed  by  J.  P.  Crozer  Griffith,  M.  D., 
Clinical  Professor  of  Diseases  of  Children,  University  of  Pennsylvania.  25 
charts  in  each  pad.     Per  pad,  50  cts.  net. 

HART'S  DIET  IN  SICKNESS  AND  IN  HEALTH. 

Diet  in  Sickness  and  Health.  By  Mrs.  Ernest  Hart,  formerly  Student 
of  the  Faculty  of  Medicine  of  Paris  and  of  the  London  School  of  Medicine 
for  Women  ;  with  an  Introduction  by  Sir  Henry  Thompson,  F.  R.  C.  S., 
M.  D.,  London.     220  pages.     Cloth,  $1.50  net. 

HAYNES'   ANATOMY. 

A  Manual  of  Anatomy.  By  IRVING  S.  Haynes,  M.  D.,  Professor  of  Prac- 
tical Anatomy  in  Cornell  University  Medical  College.  680  pages ;  42  dia- 
grams and  134  full-page  half-tone  illustrations  from  original  photographs  of 
the  author's  dissections.     Cloth,  $2.50  net. 

HEISLER'S  EMBRYOLOGY.     Second  Edition,  Revised. 

A  Text-Book  of  Embryology.  By  John  C.  Heisler.  M.  D.,  Professor  of 
Anatomy,  Mcdico-Chirurgical  College,  Philadelphia.  Octavo  volume  of  405 
pages,  handsomely  illustrated.     Cloth,  $2.50  net. 

HIRST'S  OBSTETRICS.     Third  Edition,  Revised  and  Enlarged. 

A  Text-Book  of  Obstetrics.  By  liAkfoN  CooKE  Hirst,  M.D.,  iVofessor 
of  01)stetrics,  University  of  Pennsylvani  i.  H.indsome  octavo  volume  of 
873  pigf-'S,  704  illustrations,  36  of  them  in  colors.  Cloth,  $5.00  net ;  Sheep 
or  Half  Morocco,  $6.00  net. 


MEDIC  A  L   PUBLIC  A  TIONS 


HYDE  &  MONTGOMERY  ON  SYPHILIS  AND  THE  VENEREAL 
DISEASES.    2d  Edition,  Revised  and  Greatly  Enlarged. 

Syphilis  and  the  Venerea!  Diseases.  By  James  Nevins  Hyde,  M.  D.,  Pro- 
fessor of  Skin  and  Venereal  Diseases,  and  Frank  H.  Montgomery,  M.  D., 
Associate  Professor  of  Skin,  Genito-Urinary,  and  Venereal  Diseases  in  Rush 
Medical  College,  Chicago,  111.  Octavo,  594  pages,  profusely  illustrated. 
Cloth,  ^4.00  net. 

THE  INTERNATIONAL  TEXT=BOOK  OF  SURGERY.     In  Two 
Volumes, 

Bv  American  and  British  Authors.  Edited  bv  J.  COLLINS  Warren,  M.  D., 
LL.  D.,  F.  R.C.  S.  (Hon.),  Professor  of  Surgery,  Harvard  Medical  School, 
Boston  ;  and  A.  Pearce  Gould,  M.  S.,  F.  R.  C.  S.,  Lecturer  on  Practical 
Surgery  and  Teacher  of  Operative  Surgery,  Middlesex  Hospital  Medical 
School,  London,  Eng.  Vol.  L  General  Surgery. — Handsome  octavo,  947 
pages,  with  458  beautiful  illustrations  and  9  lithographic  plates.  Vol.  IL 
Special  or  Regioial  Surgery. — Handsome  octavo,  1072  pages,  with  471 
beautiful  illustrations  and  8  hthographic  plates.  Sold  by  Subscription. 
Prices  per  volume  :  Cloth,  35.00  net:  Sheep  or  Half  Morocco,  $6.00  net. 

"  It  is  the  most  valuable  work  on  the  subject  that  has  appeared  in  some  years.  The 
clinician  and  the  pathologist  have  joined  hands  in  its  production,  and  the  result  must  be  a 
satisfaction  to  the  editors  as  it  is  a  gratification  to  the  conscientious  reader." — Annals  0/ 
Surgery. 

"  This  is  a  work  which  comes  to  us  on  its  own  intrinsic  merits.  Of  the  latter  it  has 
very  many.  The  arrangement  of  subjects  is  e.xcellent,  and  their  treatment  by  the  different 
authors  is  equally  so.  What  is  especially  to  be  recommended  is  the  painstaking  endeavor 
of  each  writer  to  make  his  subject  clear  and  to  the  point.  To  this  end  particularly  is  the 
technique  of  operations  lucidly  described  in  all  necessary  detail.  And  withal  the  work  is  up 
to  dite  in  a  very  remarkable  degree,  many  of  the  latest  operations  in  the  different  regional 
parts  of  the  body  being  given  in  full  details.  There  is  not  a  chapter  in  the  work  from  which 
the  reader  mav  not  learn  something  new." — Medical  Record,  New  York. 

JACKSON'S  DISEASES  OF  THE  EYE. 

A  Manual  of  Diseases  of  the  Eye.  By  Edward  Jack.son,  A.M.,  M.  D.. 
Emeritus  Professor  of  Diseases  of  the  Eye,  Philadelphia  Polyclinic  and  Col- 
lege for  Graduates  in  Medicine.  i2mo,  volume  of  535  pages,  with  178  illus- 
trations, mostly  from  drawings  by  the  author.     Cloth,  $2.50  net. 

KEATINQ'S  LIFE  INSURANCE. 

How  to  Examine  for  LTe  Insurance.  By  John  M.  Keating,  M.  D.,  Fellow 
of  the  College  of  Physicians  of  Philadelphia;  Ex-President  of  the  Association 
of  Life  Insurance  Medical  Directors.  Royal  octavo,  211  pages.  With 
numerous  illustrations.     Cloth,  $2.00  net. 

KEEN  ON  THE  SURGERY  OF  TYPHOID  FEVER. 

The  Surgical  Complications  and  Sequels  of  Tvphoid  Fever.  By  Wm.  W. 
Keen,  M.  D.,  LL.D..  F,  R.  C.  S.  (Hon.),  Professor  of  the  Principles  of  Sur- 
gery and  of  Clinical  Surgery,  Jefferson  Medical  College,  Philadelphia,  etc. 
Octavo  volume  of  386  pages,  illustrated.     Cloth,  $3.00  net. 

KEEN'S  OPERATION  BLANK.     Second  Edition,  Revised  Form. 

An  Operation  Blank,  with  Lists  of  Instruments,  etc.  Required  in  Various 
Operations.  Prepared  by  W.  W.  Keen,  M.  D.,  LL.D.,  F.  R.  C.S.  (Hon.), 
Professor  of  the  Principles  of  Surgery  and  of  Clinical  Surgery,  Jefferson 
Medical  College,  Philadelphia.     Price  per  pad,  of  50  blanks,  50  cts.  net. 


OF   W.  B.  SAUNDERS  d-    CO. 


KYLE  ON  THE  NOSE   AND  THROAT.     Second  Edition. 

Diseases  of  tlie  Nose  and  Throat.  By  D.  Braden  Kvle,  M.  D.,  Clinical 
Professor  of  Laryngology  and  Rhinology,  Jefferson  Medical  College,  Phila- 
delphia. Octavo,  646  pages  ;  over  150  illustrations  and  6  lithographic  plates. 
Cloth,  $4.00  net;  Sheep  or  Half  Morocco,  $5.00  net. 

LAINE'S  TEMPERATURE  CHART. 

Temperature  Chart.  Prepared  by  D.  T.  Laine,  M.  D.  Size  8  x  131^ 
inches.  A  conveniently  arranged  Chart  for  recording  Temperature,  with 
columns  for  daily  amounts  of  Urinary  and  Fecal  Excretions,  Food,  Re- 
marks, etc.  On  the  back  of  each  chart  is  given  the  Brand  treatment  of 
Typhoid  Fever.     Price,  per  pad  of  25  charts,  50  cts.  net. 

LEVY,  KLEMPERER,  AND  ESHNER'S  CLINICAL  BACTERI= 
OLOQY. 

The  Elements  of  CUnical  Bacteriolog\^  By  Dr.  Ernst  Lew,  Professor 
in  the  University  of  Strasburg,  and  Dr.  Felix  Klemperer,  Privatdocent 
in  the  University  of  Strasburg.  Translated  and  edited  by  AUGUSTUS  A. 
Eshner,  M.  D.,  Professor  of  Clinical  Medicine,  Philadelphia  Polyclinic. 
Octavo,  440  pages,  fully  illustrated.     Cloth,  $2.50  net. 

LOCKWOOD'S    PRACTICE    OF    MEDICINE.     Second   Edition, 
Revised  and  Enlarged. 

A  Manual  of  the  Practice  of  Medicine.  By  GEORGE  ROE  LoCKWOuD, 
M.  D.,  Professor  of  Practice  in  the  Women's  Medical  College. of  the  New 
York  Infirmary,  etc. 

LONG'S  SYLLABUS  OF  GYNECOLOGY. 

A  Syllabus  of  Gynecology,  arranged  in  Conformity  with  "An  American 
Text-Book  of  Gynecology."  By  J.  W.  LONG,  M.  D.,  Professor  of  Dis- 
eases of  Women  and  Children,  Medical  College  of  Virginia,  etc.  Cloth, 
interleaved.  Si. 00  net. 

MACDONALD'S   SURGICAL   DIAGNOSIS   AND  TREATMENT. 

Surgical  Diagnosis  and  Treatment.  By  J.  W.  Macdoxald,  M.  D.  Edin., 
F.  R.C.  S.  Edin.,  Professor  of  Practice  of  Surgery  and  Clinical  Surgery, 
Hamline  University.  Handsome  octavo,  800  pages,  fully  illustrated.  Cloth, 
$5.00  net;  Sheep  or  Half  Morocco,  $6.00  net. 

MALLORY   AND   WRIGHT'S  PATHOLOGICAL  TECHNIQUE. 
Second  Edition,  Revised  and  Enlarged. 

Pathological  Technique.  A  Practical  Manual  for  T^aboratory  Work  in 
Pathology,  Bacteriology,  and  Morbid  .Anatomy,  with  chapters  on  Post- 
Mortem  Technique  and  the  Performance  of  Autopsies.  By  FRANK  B. 
MaLI.ory,  a.  M.,  M.  D.,  Assistant  Professor  of  Pathology,  Harvard  Uni- 
versity .Medical  School,  l^>oston  ;  and  jAMKs  H.  Wrigiit.  A.  M.,  M.D., 
Instructor  in  Pathologv,  Harvard  University  Medical  School,  Boston. 

McFARLAND'S    PATHOGENIC    BACTERIA.      Third    Edition, 
increased   in  size  by   over   100   Pages. 

Text-Book  upon  the  Pathogenic  Bacteria.  By  JosKI'H  .McFarland, 
M.  D.,  Professor  of  Patiiology  and  Fiacteriology,  Mcdico-Chirnrgical  Col- 
Irge  of  Philadelphia,  etc.  Octavo  volume  (jf  621  pages,  finely  illustrated. 
Cloth,  $3.25  net. 


lo  MEDICAL    PUBLICATIONS 


MEIGS  ON  FEEDING  IN  INFANCY. 

Feeding  in  Early  Infancy.  By  ARTHUR  V.  Meigs,  M.  D.  Bound  in  limp 
cloth,  flush  edges,  25  cts.  net. 

MOORE'S  ORTHOPEDIC  SURGERY. 

A  Manual  of  Orthopedic  Surgery.  By  James  E.  Moore,  M.  D.,  Professor 
of  Orthopedics  and  Adjunct  Professor  of  CHnical  Surgery,  University  of 
Minnesota,  College  of  Medicine  and  surgery.  Octavo  volume  of  356  pages, 
handsomely  illustrated.     Cloth,  ^2.50  net. 

MORTEN'S  NURSES'  DICTIONARY. 

Nurses'  Dictionary  of  Medical  Terms  and  Nursing  Treatment.  Containing 
Definitions  of  the  Principal  Medical  and  Nursing  Terms  and  Abbreviations; 
of  the  Instruments,  Drugs,  Diseases,  Accidents,  Treatments,  Operations, 
Foods,  Appliances,  etc.  encountered  in  the  ward  or  in  the  sick-room.  By 
HONNOR  Morten,  author  of"  How  to  Become  a  Nurse,"  etc.  i6mo,  140 
pages.     Cloth,  ^i.oo  net. 

NANCREDE'S  ANATOMY  AND  DISSECTION.    Fourth  Edition. 

Essentials  of  Anatomy  and  Manual  of  Practical  Dissection.  By  CHARLES 
B.  Nancrede,  M.  D.',  LL.D.,  Professor  of  Surgery  and  of  Clinical  Surgery, 
University  of  Michigan,  Ann  Arbor.  Post-octavo,  500  pages,  with  full-page 
lithographic  plates  in  colors  and  nearly  200  illustrations.  Extra  Cloth  (or 
Oilcloth  for  dissection-room),  |l2.oo  net. 

NANCREDE'S  PRINCIPLES  OF  SURGERY. 

Lectures  on  the  Principles  of  Surgery.  By  CHARLES  B.  NANCREDE,  M.  D., 
LL.D,,  Professor  of  Surgery  and  of  Clinical  Surgery,  University  of  Michigan, 
Ann  Arbor.     Octavo,  398  pages,  illustrated.     Cloth,  ^2.50  net. 

NORRIS'S    SYLLABUS    OF    OBSTETRICS.      Third    Edition, 
Revised. 

Syllabus  of  Obstetrical  Lectures  in  the  Medical  Department  of  the  University 
of  Pennsylvania.  By  Richard  C.  Norris,  A.M.,  M.  D.,  Instructor  in 
Obstetrics  and  Lecturer  on  Clinical  and  Operative  Obstetrics,  University 
of  Pennsylvania.  Crown  octavo,  222  pages.  Cloth,  interleaved  for  notes, 
$2.00  net. 

OGDEN  ON  THE  URINE. 

Clinical  Examination  of  the  Urine  and  Urinary  Diagnosis.  A  Clinical  Guide 
for  the  Use  of  Practitioners  and  Students  of  Medicine  and  Surgery.  By  J. 
Bergen  Ogden,  M.  D.,  Instructor  in  Chemistry,  Harvard  University  Med- 
ical School.  Handsome  octavo,  416  pages,  with  54  illustrations,  and  a  num- 
ber of  colored  plates.     Cloth,  $3.00  net. 

PENROSE'S  DISEASES  OF  WOMEN.  Fourth  Edition,  Revised. 

A  Text-Book  of  Diseases  of  Women.  By  Charles  B.  Penrose,  M.  D., 
Ph.  D.,  formerly  Professor  of  Gynecology  in  the  University  of  Pennsylvania. 
Octavo  volume  of  538  pages,  handsomely  illustrated.     Cloth,  $3.75  net. 


OF  W.  B.   SAUNDERS  &-  CO.  ii 


PRYOR— PELVIC  INFLAMMATIONS. 

The  Treatment  of  Pelvic  Inflammations  through  the  Vagina.  By  W.  R. 
Pryor,  M.  D.,  Professor  of  Gynecology,  New  York  Polyclinic.  i2mo,  248 
pages,  handsomely  illustrated.     Cloth,  $2.00  net. 

PYE'S  BANDAGING. 

Elementary  liandaging  and  Surgical  Dressing.  With  Directions  concerning 
the  Immediate  Treatment  of  Cases  of  Emergency.  By  WALTER  Pye, 
F.  R.  C.S.,  late  Surgeon  to  St.  Mary's  Hospital,  London.  Small  i2mo, 
over  80  illustrations.     Cloth,  flexible  covers,  75  cts.  net. 

PYLE'S  PERSONAL  HYGIENE. 

A  Manual  of  Personal  Hygiene.  Proper  Living  upon  a  Physiologic  Basis. 
Edited  by  WALTER  L.  PVLE,  M.  D.,  Assistant  Surgeon  to  the  Wills  Eye 
Hospital,  Philadelphia.  Octavo  volume  of  344  pages,  fully  illustrated. 
Cloth,  $1.50  net. 

RAYMOND'S    PHYSIOLOGY.       Second    Edition,    Revised    and 
Greatly  Enlarged. 

A  Te.xt-Book  of  Physiology.  By  JOSEPH  H.  RAYMOND,  A.  M.,  M.  D.,  Pro- 
fessor of  Physiology  and  Hygiene  and  Lecturer  on  Gynecology  in  the  Long 
Island  College  Hospital. 

SALINGER  AND  KALTEYER'S  MODERN  MEDICINE. 

Modern  Medicine.  By  Julius  L.  Salinger,  M.D.,  Demonstrator  of 
Clinical  Medicine,  Jefferson  Medical  College  ;  and  F.  J.  Kalteyer,  M.  D., 
Assistant  Demonstrator  of  Clinical  Medicine,  Jefferson  Medical  College. 
Handsome  octavo,  801  pages,  illustrated.     Cloth,  $4.00  net. 

SAUNDBY'S  RENAL  AND  URINARY  DISEASES. 

Lectures  on  Renal  and  Urinary  Diseases.  By  ROBERT  Saundry,  M.  D. 
Edin.,  Fellow  of  the  Royal  College  of  Physicians,  London,  and  of  the  Royal 
Medico-Chirurgical  Society  ;  Professor  of  Medicine  in  Mason  College,  Bir- 
mingham, etc.  Octavo,  434  pages,  with  numerous  illustrations  and  4  colored 
plates.     Cloth,  $2.50  net. 

SAUNDERS'  MEDICAL  HAND=ATLASES.    See  pp.  16  and  17. 

SAUNDERS'   POCKET   MEDICAL   FORMULARY.     Sixth   Edi= 

tion,  Revised. 

By  William  M.  Powell,  M.  D.,  author  of  "Essentials  of  Diseases  of 
Children";  Member  of  Philadelphia  Pathological  Society.  Containing  1844 
formuhie  from  the  best-known  authorities.  With  an  Appendix  containing 
Posological  Table,  Formul.e  and  Doses  for  Hypodermic  Medication, 
Poisons  and  their  Antidotes,  Diameters  of  the  Female  Pelvis  and  Fetal 
Head,  01)stetrical  Table,  Diet  List  for  Various  Diseases,  Materials  and 
Drugs  used  in  Antiseptic  Surgery,  Treatment  of  Asphyxia  from  Drowning, 
Surgical  Remembrancer,  Tal)les  of  Incompatibles,  Eruptive  Fevers,  etc., 
etc.  Handsomely  bound  in  flexible  morocco,  with  side  index,  wallet,  and 
flap.     $2.00  net. 

SAUNDERS'  QUESTION-COMPENDS.     See  pages  14  and  15. 


12  MEDICAL   PUBLICATIONS 


SCUDDER'S  FRACTURES.     Second  Edition,  Revised. 

The  Treatment  of  Fractures.  By  Chas  L.  Scudder,  M.D.,  Assistant  in 
Clinical  and  Operative  Surgery,  Harvard  University  Medical  School.  Oc- 
tavo, 433  pages,  with  nearly  600  original  illustrations.  Polished  Buckram, 
$4.50  net;   Hilf  Morocco,  $5.50  net. 

SENN'S  GENITO=URINARY  TUBERCULOSIS. 

Tuberculosis  of  the  Genito -Urinary  Organs,  Male  and  Female.  By  NICH- 
OLAS Senn,  M.  D.,  Ph.  D.,  LL.D.,  Professor  of  the  Practice  of  Surgery  and 
of  Clinical  Surgery,  Rush  Medical  College,  Chicago.  Handsome  octavo 
volume  of  320  pages,  illustrated.     Cloth,  ^3.00  net. 

SENN'S  PRACTICAL  SURGERY. 

Practical  Surgery.  By  NICHOLAS  Senn,  M.  D.,  Ph.D.,  LL.D.,  Professor 
of  the  Practice  of  Surgery  and  of  Clinical  Surgery,  Rush  Medical  College, 
Chicago.  Handsome  octavo  volume  of  1200  pages,  profusely  illustrated. 
Cloth,  36.00  net ;  Sheep  or  Half  Morocco,  $7.00  net.     By  Siibscriptioii. 

SENN'S  SYLLABUS  OF  SURGERY. 

A  Syllabus  of  Lectures  on  the  Practice  of  Surgery,  arranged  in  conformity 
with  "  An  American  Text-Book  of  Surgery."  By  Nicholas  Senn,  M.  D., 
Ph.D.,  LL.D.,  Professor  of  the  Practice  of  Surgery  and  of  Clinical  Surgery. 
Rush  Medical  College,  Chicago.     Cloth,  $1.50  net. 

SENN'S  TUMORS.    Second  Edition,  Revised. 

Pathology  and  Surgical  Treatment  of  Tumors.  By  NICHOLAS  Senn,  M.  D., 
Ph.D.,  LL.D.,  Professor  of  the  Practice  of  Surgery  and  of  Clinical  Surgery, 
Rush  Medical  College,  Chicago.  Octavo  volume  of  718  pages,  with  478 
illustrations,  includidg  12  full-page  plates  in  colors.  Cloth,  $5.00  net ;  Sheep 
or  Half  Morocco,  $6.00  net. 

STARR'S  DIETS  FOR  INFANTS  AND  CHILDREN. 

Diets  for  Infants  and  Children  in  Health  and  in  Disease.  By  LOUIS  STARR, 
AL  D.,  Editor  of  "  An  American  Text-Book  of  the  Diseases  of  Children." 
230  blanks  (pocket-book  size),  perforated  and  neatly  bound  in  flexible 
morocco.     $125  net. 

STENGEL'S  PATHOLOGY.   Third  Edition,  Thoroughly  Revised. 

A  Text-Book  of  Pathology.  By  ALFRED  STENGEL.  AL  D.,  Professor  of 
Clinical  Medicine,  University  of  Pennsylvania  ;  Visiting  Physician  to  the 
Pennsylvania  Hospital.  Handsome  octavo,  873  pages,  nearly  400  illustra- 
tions, many  of  them  in  colors.  Cloth,  $5.00  net;  Sheep  or  Half  Morocco, 
^6.00  net. 

STENGEL  AND  WHITE  ON  THE  BLOOD. 

The  Blood  in  its  Clinical  and  Pathological  Relations.  By  ALFRED  Sten- 
gel. M.  D.,  Professor  of  Clinical  Medicine,  University  of  Pennsylvania;  and 
C.  Y.  White,  Jr.,  M.  D.,  Instructor  in  Clinical  Medicine,  University  of 
Pennsylvania.     In  Press. 


OF    W.    B.    SAiliXDEKS   ^    CO.  1 3 

STEVENS'  MATERIA  MEDICA  AND  THERAPEUTICS.    Third 
Edition,  Revised  and  Greatly  Enlarged. 

A  Text-Book  of  Modern  Therapeutics.  By  A.  A.  Stevens,  A.  M.,  M.  D., 
Lecturer  on  Physical  Diagnosis  in  the  University  of  Pennsylvania. 

STEVENS'  PRACTICE  OF  MEDICINE.     Fifth  Edition,  Revised, 

A  Manual  of  the  Practice  of  Medicine.  By  A.  A.  STEVENS,  A.  M.,  M.  D., 
Lecturer  on  Physical  Diagnosis  in  the  University  of  Pennsylvania.  Spe- 
cially intended  for  students  preparing  for  graduation  and  hospital  examina- 
tions.    Post-octavo,  519  pages  ;  illustrated.     Flexible  Leather,  ^2.00  net. 

STEWART'S  PHYSIOLOGY.     Fourth  Edition,  Revised. 

A  Manual  of  Physiology,  with  Practical  Exercises.  For  Students  and  Prac- 
titioners. By  G.  N.  Stewart,  M.  A.,  M.  D.,  D.  Sc.  Professor  of  Physiol- 
ogy in  the  Western  Reserve  University,  Cleveland,  Ohio.  Octavo  volume 
of  894  pages  ;  336  illustrations  and  5  colored  plates.     Cloth,  $3.75  net. 

STONEY'S  MATERIA  MEDICA  FOR  NURSES. 

Materia  Medica  for  Nurses,  By  Emily  A.  M.  Stoney,  late  Superintend- 
ent of  the  Training-School  for  Nurses,  Carney  Hospital,  South  Boston, 
Mass.     Handsome  octavo  volume  of  306  pages.     Cloth,  $1.50  net. 

STONEY'S  NURSING.    Second  Edition,  Revised. 

Practical  Points  in  Nursing.  For  Nurses  in  Private  Practice.  By  Emii,Y 
A.  M.  Stoney,  late  Superintendent  of  the  Training-School  for  Nurses, 
Carney  Hospital,  South  Boston,  Mass.  456  pages,  with  73  engravings  and 
8  colored  and  half-tone  plates.     Cloth,  $1.75  net. 

STONEY'S  SURGICAL  TECHNIC  FOR  NURSES. 

Bacteriology  and  Surgical  Technic  for  Nurses.  By  EMILY  A.  M.  Stoney, 
late  Superintendent  of  the  Training-School  for  Nurses,  Carney  Hospital, 
South  Boston,  Mass.     i2mo  volume,  fully  illustrated.     Cloth,  ^1.25  net. 

THOMAS'S  DIET  LISTS.     Second  Edition,  Revised. 

Diet  Lists  and  Sick-Room  Dietarv.  By  Jerome  B.  Thom.a.s,  M.D.,  In- 
structor in  Materia  Medica,  Long  Island  Hospital ;  Assistant  Bacteriologist 
to  the  Hoagland  Laboratory.     Cloth,  $1.25  net.     Send  for  sample  sheet. 

THORNTON'S  DOSE=BOOK  AND  PRESCRIPTION=WRITING. 
Second  Edition,  Revised  and  Enlarged. 

Dose-Book  and  Manual  of  Prescripti.n- Writing.  By  E.  Q.  TlIORNTON, 
M.D.,  Demonstrator  of  Therapeutics,  Jefferson  Medical  College,  Philadel- 
phia. 

VAN  VALZAH  AND  NISBET'S  DISEASES  OF  THE  STOMACH. 

Di-seases  of  the  Stomach.  By  WlI.LIA.M  W.  VAN  Val/.aii,  .M.  D.,  Pro- 
fessor of  General  Medicine  and  Diseases  of  the  Digestive  System  and  the 
Blood,  New  York  Polyclinic;  and  J.  DOUGLAS  Nisbet,  M.  D.,  Adjunct 
Professor  of  General  Medicine  and  Diseases  of  the  Digestive  System  and 
the  Blood,  New  York  Polyclinic.  Octavo  volume  of  674  pages,  illustrated. 
Cloth,  1513.50  net. 


14  MEDICAL    PUBLICATIONS. 


VECKI'S  SEXUAL  IMPOTENCE.    Second  Edition,  Revised. 

The  I'athology  and  Treatment  of  Sexual  Impotence.  By  VICTOR  G.  Vecki, 
M.  D.  From  the  second  German  edition,  revised  and  enlarged.  Demi- 
octavo,  291  pages.     Cloth,  ^2.00  net. 

VIERORDT'S    MEDICAL    DIAGNOSIS.      Fourth    Edition,   Re= 
vised. 

Medical  Diagnosis.  By  Dr.  Oswald  Vierordt,  Professor  of  Medicine, 
University  of  Heidelberg.  Translated,  with  additions,  from  the  fifth  en- 
larged German  edition,  with  the  author's  permission,  by  Francis  H. 
Stliart,  A.  M.,  M.D.  Handsome  octavo  volume,  603  pages;  194  wood- 
cuts, many  of  them  in  colors.  Cloth,  4.00  net ;  Sheep  or  Half-Morocco. 
^5.00  net. 

WATSON'S  HANDBOOK  FOR  NURSES. 

A  Handbook  for  Nurses.  Bv  J.  K.  Watson,  M.D.  Edin.  American 
Edition,  under  supervision  of  .A.  A.  Stevens,  A.M.,  M.  D.,  Lecturer  on 
Physical  Diagnosis,  University  of  Pennsylvania.  i2mo,  413  pages,  73  illus- 
trations.    Cloth,  $1.50  net. 

WARREN'S  SURGICAL  PATHOLOGY.     Second  Edition. 

Surgical  Pathology  and  Therapeutics.  By  JOHN  COLLINS  Warren,  M.  D., 
LL.D.,  F.  R.  C.  S.  (Hon.),  Professor  of  Surgery,  Harvard  Medical  School. 
Handsome  octavo,  873  pages  ;  136  relief  and  lithographic  illustrations,  33  in 
colors.  With  an  Appendix  on  Scientific  Aids  to  Surgical  Diagnosis,  and  a 
•  series  of  articles  on  Regional  Bacteriology.  Cloth,  ^5.00  net ;  Sheep  or 
Half  Morocco,  ^6,00  net. 


SAUNDERS' 
QUESTION  =  COMPENDS. 


ARRANGED  IN  QUESTION  AND  ANSWER  FORM. 


The  Most  Complete  and  Best  Illustrated  Series  of  Compends  Ever  Issued. 


NOW  THE  STANDARD  AUTHORITIES  IN  MEDICAL  LITERATURE 

WITH 

Students  and  Practitioners  in  every  City  of  the  United  States  and  Canada. 


Since  the  issue  of  the  first  volume  of  the  Saunders  Question-Compends, 

OVER  200,000  COPIES 

of    these   unrivalled    publications    have   been   sold.      This   enormous   sale   is   indisputable 
evidence  of  the  value  of  these  self-helps  to  students  and  physicians. 

SEE  NEXT  PAGE  FOR  LIST. 


Sau  nders' 
Question  =  Compend    Series. 

Price,  Cloth,  $i.oo  net  per  copy,  except  when  otherwise  noted. 


"  Where  the  work  of  preparing  students'  manuals  is  to  end  we  cannot  say,  but  the  Saunders 
Series,  in  our  opinion,  bears  off  the  palm  at  present." — New  York  Medical  Record. 


1.  Essentials    of    Physiology.       By   Sidney    Budgett,    M.  D.     An   entirely   new 

ivoik. 

2.  Essentials  of  Surgery.     By  Edward  Martin,  M.  D.     Seventh  edition,  revised 

with  an  Appendix  and  a  chapter  on  Appendicitis.  '  ' 

3.  Essentials  of  Anatomy.     By  Charles   B.    Nancrede,    M.  D.     Sixth   edition 

thoroughly  revised  and  enlarged.  ' 

4.  Essentials  of  Medical  Chemistry,  Organic  and  Inorganic.    By  Lawrence 

Wolff,  M.  D.     Fifth  edition,  revised. 

5.  Essentials  of  Obstetrics.     By  W.  Easterly  Ashton,  M.  D.     Fourth  edition, 

revised  and  enlarged. 

6.  Essentials  of  Pathology  and  Morbid  Anatomy.    By  f.  j.  Kalteyer,  m.  d. 

In  preparation. 

7.  Essentials  of  Materia  Medica,  Therapeutics,  and  Prescription-Writing. 

By  Henry  Morris,  M.  D.     Fifth  edition,  revised. 

8.  9.     Essentials  of  Practice   of  Medicine.     By  Henry  Morris,  M.  D.     An  Ap- 

pendix on  Urine  Examination.  By  Lawrence  Wolff,  M.  D.  Third  edition, 
enlarged  by  some  300  Essential  Formulae,  selected  from  eminent  authorities,  by 
Wm.  M.  Powell,  M.  D.     (Double  number,  ;$i.5o  net.) 

10.  Essentials    of    Gynecology.     By    Edwin   B.   Cr.\gin,   M.  D.         Fifth     edition, 

revised. 

11.  Essentials  of  Diseases  of  the  Skin.    By  Henry  w.  Stelwagon,  m.  d. 

Fourth  edition,  revised  and  enlarged. 

12.  Essentials  of  Minor  Surgery,  Bandaging,  and  Venereal  Diseases.    By 

Edward  Martin,  IVL  D.     Second  edition,  revised  and  enlarged. 

13.  Essentials  of  Legal  Medicine,  Toxicology,  and  Hygiene.    This  volume  is 

at  present  out  of  print. 

14.  Essentials    of  Diseases    of  the   Eye,     By    Edward   Jackson,    M.  D.     Third 

edition,  revised  and  enlarged. 

16.     Essentials  Of  Diseases  Of  Children.     By  William  M.  Powell,  M.  D.    Third 

16.  Essentials  Of  Examination  Of  Urine.     By  Lawrence  Wolff,  M.  D.     Colored 

"  VoGEL  Scale."     (75  cents  net.) 

17.  Essentials  of  Diagnosis.     By  S.  Solis-Cohen,  ]\L  D.,  and  A.  A.  Eshner,  M.  D. 

Second  edition,  thoroughly  revised. 

18.  Essentials  of  Practice  of  Pharmacy.     By  Lucius  E.  Sayre.     Second  edition, 

revised  and  enlarged. 

19.  Essentials  of  Diseases  of  the  Nose  and  Throat.    By  E.  B.  Glbasqn,  M.  D 

Third  edition,  revised  and  enlarged. 

20.  Essentials  of  Bacteriology.     By  M.  V.  Ball,  M.  D.     Fourth  edition,  revised. 

21.  Essentials  of  Nervous  Diseases  and  Insanity.    By  John  c.  Shaw,  M.  D. 

Third  edition,  revised. 

22.  Essentials  of  Medical  Physics,     By  Fred  J.  Brockway,  M.  D.     Second  edi- 

tion, revised. 

23.  Essentials  of  Medical  Electricity.     By  David  D.  Stewart,  M.  D.,  and   Ed- 

ward S.  Law  ranch,  M.  D. 

24.  Essentials  of  Diseases  of  the  Ear.     By  E.  B.Gleason,  M.  D.     Second  edition, 

revised  and  greatly  enlarged. 

25.  Essentials  of  Histology.     By  Louis  Lrroy.  M.  D.     With  73  original  illustrations. 

Pamphlet  containing  specimen  pages,  etc.,  sent  free  upon  application. 

15 


Saunders'  Medical  Hand=Atlases. 

VOLUMES  NOW  READY. 

ATLAS    AND    EPITOME    OF    INTERNAL    MEDICINE    AND 
CLINICAL    DIAGNOSIS. 

By  Dk.  Chk.  JAKOi:,  of  Krlangen.  Edited  by  AUGUSTUS  A.  ESHNER, 
M.  D.,  Professor  of  Clinical  Medicine,  Philadelphia  Polyclinic,  With  179 
colored  figures  on  68  plates,  64  text-illustrations,  259  pages  of  text.  Cloth, 
^3.00  net. 

ATLAS  OF  LEGAL  MEDICINE. 

By  Dr.  E.  R.  vox  Hofiman.  of  Vienna.  Edited  by  Frederick  Peter- 
son, M.  D.,  Chief  of  Clinic,  Nervous  Department,  College  of  Physicians  and 
Surgeons,  New  York.  With  120  colored  figures  on  56  plates  and  193  beau- 
tiful half-tone  illustrations.     Cloth,  $3. 50  net. 

ATLAS  AND  EPITOME  OF  DISEASES  OF  THE  LARYNX. 

By  Dr.  L.  Grunwald,  of  Munich.  Edited  by  Charles  P.  Grayson. 
M.  D.,  Physician-in-Charge,  Throat  and  Nose  Department,  Hospital  of  the 
University  of  Pennsylvania.  With  107  colored  figures  on  44  plates,  25  text- 
illustrations,  and  103  pages  of  text.     Cloth,  S2.50  net. 

ATLAS  AND  EPITOME  OF  OPERATIVE  SURGERY. 

By  Dr.  O.  Zuckerk.'VXDL,  of  Vienna.  Edited  by  J.  Chalmers  DaCosta, 
M.  D.,  Professor  of  Principles  of  Surgery  and  Clinical  Surgery,  Jefferson 
Medical  College,  Philadelphia.  With  24  colored  plates,  214  text-illustra- 
tions, and  395  pages  of  text.     Cloth,  53.00  net. 

ATLAS  AND  EPITOME  OF  SYPHILIS  AND  THE  VENEREAL 
DISEASES. 

By  Prof.  Dr.  Franz  Mracek,  of  Vienna.  Edited  by  L.  Bolton  Bangs, 
M.  D.,  Professor  of  Genito-Urinnry  Surgery,  University  and  Bellevue  Hos- 
pital Medical  College,  New  York.  With  71  colored  plates,  16  illustrations, 
and  122  pages  of  text.     Cloth,  $3.50  net. 

ATLAS  AND  EPITOME  OF  EXTERNAL  DISEASES  OF  THE 
EYE. 

By  Dr.  O.  Haab,  of  Zurich.  PMited  by  G.  E.  DE  SCHWEINITZ,  M.  D., 
Professor  of  Ophthalmology,  Jefferson  Medical  College,  Philadelphia.  With 
76  colored  illustrations  on  40  plates  and  228  pages  of  text.     Cloth,  $3.00  net. 

ATLAS  AND  EPITOME  OF  SKIN  DISEASES. 

By  Prof.  Dr.  Fr.\nz  Mracek,  of  Vienna.  Edited  by  Henry  W.  Stel- 
WAGON.  M.  D.,  Clinical  Professor  of  Dermatology,  Jefferson  Medical  Col- 
lege, Philadelphia.  With  63  colored  plates,  39  half-tone  illustrations,  and 
200  pages  of  text.     Cloth,  $3.50  net. 

ATLAS  AND   EPITOME  OF  SPECIAL  PATHOLOGICAL  HIS= 
TOLOGY. 

By  Dr.  H.  Durck,  of  Munich.  Edited  by  LUDWIG  HektOEN,  M.  D., 
Professor  of  Patholog\',  Rush  Medical  College,  Chicago.  In  Two  Parts. 
Part  I.  Ready,  including  Circulatory,  Respiratory,  and  Gastro-intestinal 
Tract,  120  colored  figures  on  62  plates,  158  pages  of  text.  Part  II.  Ready 
Shortly.     Price  of  Part  I.,  $3.00  net. 

16 


Saunders'  Medical  Iiand=Atlases. 


VOLUMES  JUST  ISSUED. 

ATLAS   AND  EPITOME   OF   DISEASES  CAUSED   BY   ACCI- 
DENTS. 

By  Dr.  Ed.  Golebiewski,  of  Berlin.  Translated  and  edited  with  addi- 
tions by  Pearce  Bailey,  M.  D.,  Attending  Physician  to  the  Department 
of  Corrections  and  to  the  Ahnshouse  and  Incurable  Hospitals,  New  York. 
With  40  colored  plates,  143  text-illustrations,  and  600  pages  of  text.  Cloth, 
$4.00  net. 

ATLAS  AND  EPITOME  OF  GYNECOLOGY. 

By  Dr.  O.  Shaeffer,  of  Heidelberg.  From  the  Second  Revised  Gerinan 
Edition.  Edited  by  RICHARD  C.  NORRIS,  A.  M.,  M.D..  Gynecologist  to 
the  Methodist  Episcopal  and  the  Philadelphia  Hospitals;  Surgeon-in-Charge 
of  Preston  Retreat,  Philadelphia.  With  90  colored  plates,  65  text-illustra- 
tions, and  308  pages  of  text.     Cloth,  $3.50  net. 

ATLAS   AND    EPITOME  OF   THE   NERVOUS  SYSTEM   AND 
ITS  DISEASES. 

By  Professor  Dr.  Chr.  Jakob,  of  Erlangen.  From  the  Second  Revised 
and  Enlarged  German  Edition.  Edited  by  Edward  D.  Fisher,  M.  D., 
Professor  of  Diseases  of  the  Nervous  System,  University  and  Bellevue  Hos- 
pital Medical  College,  New  York.  With  83  plates  and  a  copious  text. 
$3  50  net. 

ATLAS   AND   EPITOME  OF   LABOR    AND  OPERATIVE    0B= 
STETRICS. 

By  Dr.  O.  Shaeffer,  of  Heidelberg.  From  the  Fifth  Revised  and  Enlarged 
German  Edition.  Edited  by  J.  CLIFTON  Edgar,  M.  D.,  Professor  of  Ob- 
stetrics and  Clinical  Midwifery,  Cornell  University  Medical  Scliool.  W.th 
126  colored  illustrations.     %2..oo  net. 

ATLAS  AND  EPITOME  OF   OBSTETRICAL  DIAGNOSIS  AND 
TREATMENT. 

By  Dr.  O.  Shaeffer,  of  Heidelberg.  From  the  Second  Revised  and  En- 
larged German  Edition.  Edited  by  J.  CliftoN  Edgar,  M.  D.,  Professor 
of  Obstetrics  and  Clinical  Midwifery,  Cornell  University  Medical  School. 
72  colored  plates,  numerous  text-illustrations,  and  copious  text.     ^300  net. 

ATLAS  AND  EPITOME  OF  OPHTHALMOSCOPY   AND  OPH- 
THALMOSCOPIC DIAGNOSIS. 

By  Dr.  O.  Haab,  of  Zurich.  From  the  Third  Revised  and  Enlarged  Ger- 
tnan  Edition.  Etlited  by  G.  E.  DE  ScHWElNnv,,  M.  D.,  Professor  of  Oph- 
thalmolf)gy,  Jefferson  Medical  College,  Philadelphia.  With  152  colored 
figures  anrl   82  pages  of   text.      Cloth.  S3.00  n<t. 

ATLAS  AND   EPITOME  OF   BACTERIOLOGY. 

Including  a  Hand-Fiook  of  Special  liactcrioUjgii  Diagnosis.  By  PkoF.  Dr. 
K.  B.  Eehman.n  and  Dr.  R.  O.  Nkuma.NN,  of  Wurzlmrg.  From  the  Second 
Re-.'ised  German  Edition.  I'Mited  by  (iEOR(;E  H.  WEAVER.  M.  D.,  As-istant 
Professor  of  Pathology  and  Bacteriology,  Rush  .Medical  College,  Chicago. 
Two  volumes,  with  over  600  colored  lithographic  figures,  numerous  text- 
illustrations,  and  500  pages  of  text. 


Nothnagel's  Encyclopedia 

OF 

PRACTICAL    MEDICINE. 

Edited  by  ALFRED  STENGEL,  M.  D., 

Professor  of  Clinical  Medicine  in  the  University  of  Pennsylvania;  Visiting 
Physician  to  the  Pennsylvania  Hospital. 

IT  is  universally  acknowledged  that  the  Germans  lead  the  world  in  Internal  Medicine ; 
and  of  all  the  German  works  on  this  subject,  Nothnagel's  "  Special  Pathology  and 
Therapeutics "  is  conceded  by  scholars  to  be  without  question  the  best  System  of 
Medicine  in  existence.  So  necessary  is  this  book  in  the  study  of  Internal  Medicine 
that  it  comes  largely  to  this  country  in  the  original  German.  In  view  of  these  facts, 
Messrs.  W.  B.  Saunders  &  Company  have  arranged  with  the  publishers  to  issue  at  once 
an  authorized  edition  of  this  great  encyclopedia  of  medicine  in  English. 

For  the  present  a  set  of  some  ten  or  twelve  volumes,  representing  the  most  practical 
part  of  this  encyclopedia,  and  selected  with  especial  thought  of  the  needs  of  the  practical 
physician,  will  be  published.  These  volumes  will  contain  the  real  essence  of  the  entire 
work,  and  the  purchaser  will  therefore  obtain  at  less  than  half  the  cost  the  cream  of  the  origi- 
nal.    Later  the  special  and  more  strictly  scientific  volumes  will  be  offered  from  time  to  time. 

The  work  will  be  translated  by  men  possessing  thorough  knowledge  of  both  English  and 
German,  and  each  volume  will  be  edited  by  a  prominent  specialist  on  the  subject  to 
which  it  is  devoted.  It  will  thus  be  brought  thoroughly  up  to  date,  and  the  American  edition 
will  be  more  than  a  mere  translation  of  the  German  ;  for,  in  addition  to  the  matter  contained 
in  the  original,  it  will  represent  the  very  latest  views  of  the  leading  American  special- 
ists in  the  various  departments  of  Internal  Medicine.  The  whole  System  will  be  under  the 
editorial  supervision  of  Dr.  Alfred  Stengel,  who  will  select  the  subjects  for  the  American 
edition,  and  will  choose  the  editors  of  the  different  volumes. 

Unlike  most  encyclopedias,  the  pub1':ation  of  this  work  will  not  be  extended  over  a 
number  of  years,  but  five  or  six  volumes  will  be  issued  during  the  coming  year,  and  the 
remainder  of  the  series  at  the  same  rate.  Moreover,  each  volume  will  be  revised  to  the 
date  of  its  publication  by  the  American  editor.  This  will  obviate  the  objection  that  has 
heretofore  existed  to  systems  published  in  a  number  of  volumes,  since  the  subscriber  will 
receive  the  completed  work  while  the  earlier  volumes  are  still  fresh. 

The  usual  method  of  publishers,  when  issuing  a  work  of  this  kind,  has  been  to  compel 
physicians  to  take  the  entire  System.  This  seems  to  us  in  many  cases  to  be  undesirable. 
Therefore,  in  purchasing  this  encyclopedia,  physicians  will  be  given  the  opportunity  of 
subscribing  for  the  entire  System  at  one  time;  but  any  single  volume  or  any  number  of 
volumes  may  be  obtained  by  those  who  do  not  desire  the  complete  series.  This  latter 
method,  while  not  so  profitable  to  the  publisher,  offers  to  the  purchaser  inany  advan- 
tages which  will  be  appreciated  by  those  who  do  not  care  to  subscribe  for  the  entire  work 
at  one  time. 

This  American  edition  of  Nothnagel's  Encyclopedia  will,  without  question,  form  the 
greatest  System  of  Medicine  ever  produced,  and  the  publishersfeel  confident  that  it 
will  meet  with  general  favor  in  the  medical  profession. 


NOTHNAGEL^S  ENCYCLOPEDIA 

VOLUMES   JUST  ISSUED  AND  IN  PRESS 


VOLUME  I 

Editor,  William  Osier,  M.  D., 

F.R.CR 

Professor  of  Medicine  in  Johns  Hopkins 
University 

CONTENTS 

Typhoid  Fever.  By  Dr.  H.  Cukschmann, 
ul"  Leipsic,  Typhus  Fever.  By  Dr.  H. 
Cukschmann,  of  Leipsic. 

Handsome  octavo  volume  of  about  600  pages. 
Just  Issued 


VOLUME  n 

Editor,  Sir  J,  W.  Moore,  B.  A.,  M.  D., 

F.R.CP.L,  of  Dublin 

Professor  of  Practice  of  Medicine,  Royal 
College  of  Surgeons  in  Ireland 

CONTENTS 

Erysipelas  and  Erysipeloid.  By  Dr.  H. 
Lenhartz,  of  Hamburg.  Cholera  Asi- 
atica  and  Cholera  Nostras  By  Dr 
K.  V(jn  Liecermeistek,  of  lijbingen 
Whooping  Cough  and  Hay  Fever.  By 
Dk.  (t.  Sticker,  of  Giessen.  Varicella 
By  Dr.  Th.  vo.n  Jurgense.n,  of  Tiibingen 
Variola  (including  Vaccination).  B\ 
Dr.  H.  Immekmann,  of  Basle. 

Handsome  octavo  volume  of  over  700  pages. 
Just  Issued 


VOLUME  vn 

Editor,  John  H.  Musser,  M.  D. 

Professor  of  Clinical  Medicine ,  L'>iiversity 
of  Pennsylz'u)iia 

CONTENTS 

Diseases  of  the  Bronchi.  By  Dr.  F.  A. 
Hoffmann,  of  Leipsic.  Diseases  of  the 
Fleura.  By  Dk.  Rosenbach,  of  Berlin. 
Pneumonia.  By  Dk.  E.  Alfrecht,  of 
Magdeburg. 


VOLUME  VIU 
Editor,  Charles  G.  Stockton,  M.  D. 

Professor  of  Medicine,  University  of  Buffalo 

CONTENTS 

Diseases    of  the    Stomach.      By  Du.    F. 
RiEGEL,  of  Giessen. 


VOLUME  EX 
Editor,  Frederick  A.  Packard,  M.  D. 

Physician  to  the  Pennsylvania  Hospital  and 
to  the  Children's  Hospital,  Philadelphia 

CONTENTS 
Diseases    of   the     Liver.       By    Drs.    H. 

fjLINCKE   and    Cj.   HrippE-SEVLER,  of  Kiel. 


VOLUME  m 
Editor,  William  P.  Northrup,  M.  D. 

Professor  of  Pediatrics,  University  and 
Bellevue  Medical  College 

CONTENTS 
Measles.     By  I)k.   In.  von  Jurcensen,  of 
Tiibingen.     Scarlet  Fever.    By  the  same 
author.     Rotheln.    I'.y  the  same  author. 


VOLUME  VI 
Editor,  Alfred  Stengel,  M.  D. 

J'rofessor  of  Clinical  Medic i>ie.  University 
of  Pennsyh'ania 

CONTENTS 

Anemia.  I'>y  Dk.  I'.  Kiiki.k  ir,  of  Frank- 
lort-on-the-.\Iain,  and  I)k.  A.  Lazaris,  of 
Cjharloitenburg.  Chlorosis.  By  \)\<.  K. 
V'>N  Nf)ORi)F.N,  of  Fr.-inklorl-on  the-.\Iain. 
Diseases  of  the  Spleen  and  Hemor- 
rhagic Diathesis.  By  Dk.  AL  Litien, 
ot   Berlin. 


VOLUME  X 
Editor,  Reginald  H.  Fitz,  A,  M.,  M.D. 

Hct  sey  Professor  of  the  Theory  and  Prac- 
tice of  Physic,  Harvard  University 

CONTENTS 

Diseas  s  of  the  Pancreas.  By  Dr.  L. 
(JsER,  of  Vienna.  Diseases  of  the  Supra- 
renals.     By  Dk.  K.  Nfissei,  of  \  ienna. 


VOLUMES  IV,  V,  and  XI 

Editors  announced  later 

Vol.  IV. — Influenza  and  Dengue.  By  Dr. 
<).  Lekhtenstein,  of  Cologne.  Malarial 
Diseases.     By    Dr.    J.    Mannaiserc;,   of 

\  iciina. 

Vol. v.— Tuberculosis  and  Acute  General 
Miliary  Tuberculosis.  By  Dk.  (1.  Cor- 
Ni:r,  (jf  I'erlin. 

Vol.  X  I.  -Diseases  of  th-  Intestines  and 
Peritoneum.  By  Dk.  H.  Nothnauel, 
of  N'ienna. 


19 


CLASSIFIED  LIST 

OF  THE 

MEDICAL    PUBLICATIONS 


OF 


W.  B.  SAUNDERS  &  COMPANY 


ANATOMY,  EMBRYOLOGY,  HIS- 
TOLOGY. 

Bohm,  Davidoff,  and  Huber — A  Text- 
Book  of  Histology, 4 

Clarkson — A  Text-Book  of  Histology,   .  5 

Haynes — A  Manual  of  Anatomy,    ...  7 

Heisler — A  Text-Book  of  Embryology,  .  7 

Leroy — Essentials  of  Histology,     ....  15 

Nancrede — Essentials  of  Anatomy,  .    .    .  15 
Nancrede — Essentials  of  Anatomy  and 

Manual  of  Practical  Dissection,  ....  10 

BACTERIOLOGY. 

Ball — Essentials  of  Bacteriology,  ....    15 

Frothingham  — Laboratory  Guide,  .    .    .      6 

Gorham — Laboratory  Course  in  Bacte- 
riology,     22 

Lehmann  and  Neumann — Atlas  of 
Bacteriology 17 

Levy  and  Klemperer's  Clinical  Bacte- 
riologry, 9 

Mallory  and  Wright — Pathological 
Technique, 9 

McFarland — Pathogenic  Bacteria,  ...     9 

CHARTS,  DIET-LISTS,  ETC. 

Griffith — InfaHt's  Weight  Chart,  ....  7 

Hart — Diet  in  Sickness  and  in  Health,    .  7 

Keen — Operation  Blank, 8 

Laine — Temperature  Chart, 9 

Meigs — Feeding  in  Early  Infancy,    ...  10 

Starr — Diets  for  Infants  and  Children,  .  12 

Thomas — Diet-Lists, 13 

CHEMISTRY  AND  PHYSICS. 
Brock  way — Essentials    of    Medical 

Physics, 15 

Wolff — Essentials  of  Medical  Chemistry,    15 

CHILDREN. 
An  American   Text-Book  of  Diseases 

of  Children, i 

Griffith — Care  of  the  Baby 7 

Griffith— Infant's  Weight  Chart,  ....  7 
Meigs — Feeding  in  Early  Infancy,   ...  10 
Powell — Essentials  of  Diseases  of  Chil- 
dren,    .        15 

Starr — Diets  for  Infants  and  Children,    .  12 

DIAGNOSIS. 

Cohen  and  Eshner — Essentials  of  Diag- 
nosis  15 

Corwin — Physical  Diagnosis, 5 

Vierordt — Medical  Diagnosis, 14 

DICTIONARIES. 
The    American    Illustrated     Medical 

Dictionary 3 

The   American   Pocket   Medical    Dic- 

3 

Dictionary, 10 


tionary,    .    .    .    . 
Morton — Nurses' 


EYE,  EAR,  NOSE,  AND  THROAT. 

An  American   Text-Book  of  Diseases 

of  the  Eye,  Ear,  Nose,  and  Throat,  .    .      i 
De  Schweinitz— Diseases  of  the  Eye,    .     6 
Friedrich  and  Curtis — Rhinology,  Lar- 
yngology, and  Otology, 6 

Gleason  —  Essentials  of  the  Ear,    ....    15 
Gleason — Essentials  of  Nose  and  Throat,  15 
Gradle — Ear,  Nose. and  Throat,  ....    22 
Grunw^ald  and  Grayson — Atlas  of  Dis- 
eases ot  the   Laryn.v, 16 

Haab  and  de  Schweinitz — Atlas  of  Ex- 
ternal Diseases  of  the  Eye, i6 

Jackson — Manual  of  Diseases  of  the  Eye,  8 
Jackson — Essentials  Diseases  of  Eye,  .  15 
Kyle — Diseases  of  the  Nose  and  Throat,     9 

GENITO-URINARY. 

An  American  Text-Book  of  Genito- 
urinary and  Skin  Diseases, 2 

Hyde  and  Montgomery — Syphilis  and 
the  Venereal  Diseases, 8 

Martin — Essentials  of  Minor  Surgery, 
Bandaging,  and  Venereal  Diseases,  .    .    15 

Mracek  and  Bangs — Atlas  of  Syphilis 
and  the  Venereal   Diseases, 16 

Saundby — Renal  and  Urinary  Diseases,    11 

Senn — Genito-Urinary  Tuberculosis,    .    .    12 

Vecki — Sexual  Impotence, 14 

GYNECOLOGY. 

American  Text-Book  of  Gynecology,   .  a 

Cragin — Essentials  of  Gynecology,  ...  15 

Garrigues — Diseases  of  Women,  .    ...  6 

Long — Syllabus  of  Gynecology,    ....  9 

Penrose — Diseases  of  Women, 10 

Pryor — Pelvic  Inflammations, 11 

Schaeffer  and  Norris — Atlas  of  Gyne- 
cology,       jj 

HYGIENE. 

Abbott — Hygiene  of  Transmissible  Dis- 
eases,     3 

Bergey — Principles  of  Hygiene,  ....  22 
Pyle — Personal  Hygiene, 11 

MATERIA      MEDICA,      PHARMA- 
COLOGY, and  THERAPEUTICS. 
An  American   Text-Book  of  Applied 

Therapeutics, i 

Butler — Text-Book    of  Materia  Medica, 

Therapeutics,  and  Pharmacology,  .  .  4 
Morris— Ess. of  M.  M.  and  Therapeutics,  15 
Saunders'  Pocket  Medical  Formulary,  .    11 

Sayre — Essentials  of  Pharmacy 15 

Sollmann — Text-Book  of  Pharmacology,  22 
Stevens — Modern  Therapeutics,  ....  13 
Stoney — Materia  Medica  for  Nurses,  .  .  13 
Thornton — Prescription-Writing,     ...    13 


20 


MEDICAL  PUBLICATIONS 


21 


MEDICAL  JURISPRUDENCE  AND 
TOXICOLOGY. 

Chapman— Medical  Jurisprudence  and 
Toxicology 5 

Golebiewski  and  Bailey — Atlas  of  Dis- 
eases Caused  by  Accidents, 17 

Hofmann  and  Peterson— Atlas  of  Legal 
Medicine,         16 

NERVOUS   AND   MENTAL  DIS- 
EASES, ETC. 

Brower — Manual  of  Insanity, 22 

Chapin — Compendium  of  Insanity.  ...  5 
Church    and    Peterson — Nervous  and     5 

Mental  Diseases 5 

Jakob  and   Fisher — Atlas   of    Nervous 

System, 17 

Shavvr — Essentials  of  Nervous  Diseases 

and  Insanity, 15 

NURSING. 
Davis — Obstetric  and  Gynecologic  Nurs 


ingj 


Griffith— The  Care  of  the  Baby,  .  . 
Hart — Diet  in  Sickness  and  in  Health, 
Meigs — Feeding  in  Early  Infancy,  . 
Morten — Nurses'  Dictionary,  .  .  . 
Stoney — Materia  Medica  for  Nurses, 
btoney — Practical  Points  in  Nursing,  . 
Stoney — Surgical  Technic  for  Nurses, 
Watson — Handbook  for  Nurses,  .    .    . 

OBSTETRICS. 

An  American  Text-Book  of  Obstetrics, 
Ashton — Essentials  of  Obstetrics,  . 
Boisliniere — Obstetric  Accidents 
Dorland — Modern  Obstetrics,  . 
Hirst — Text-Book  of  Obstetrics, 
Norris — Syllabus  of  Obstetrics,  . 
Schaeffer  and  Edgar — Atlas  of  Obstet- 
rical Diagnosis  and  Treatment,  ... 


17 


PATHOLOGY. 

An  American  Text-Book  of  Pathology,     2 
Durck  and  Hektoen — Atlas  of  Patho- 
logic  Histology, 16 

Kalteyer — Essentials  of  Pathology,    .    .    15 
Mallory    and    Wright  —  Pathological 

Technique, 9 

Senn — Pathology,  and    Surgical    Treat- 
ment of  Tumors, 12 

Stengel— Text-Book  of  Pathology,  ...    12 
\A/arren — Surgical  Pathology,    ....        14 

PHYSIOLOGY. 

American  Text-Book  of  Physiology,  .  2 

Budgett — I'.sscntials  of  Physiology,    .    .  15 

Raymond — Text-Book  of  Physiology,  .  11 

Stewart — Manual  of  Physiology,    .    .  13 

PRACTICE   OF  MEDICINE. 


)f  Medic 


An  American  Year-Book 

and  Surgery 

Anders— Practice  of  Mcflirinc.  .    . 
Eichhorst —Practice  of  Medicine, 
Lockwood  -Prai  til  o  f)f  Medicine, 
Morris — l-'ss.  iS  Pr;icti<:f  of  Mi-dicine, 
Salinger  &  Kalteyer— Mod.  Medicine,    11 
Stevens     l'r.-i<  lii  <•  i.l   Mcdii  Inf,    .    .    .        i^ 


SKIN  AND  VENEREAL. 

An  American  Text-Book  of  Genito- 
urinary and  Skin  Diseases, 2 

Hyde  and  Montgomery — Syphilis  and 
the  Venereal  Diseases, 8 

Martin  —  Essentials  of  Minor  Surgery, 
Bandaging,  and  Venereal  Diseases,  .    .    15 

Mracek  and  Stelwagon— Atlas  of  Dis- 
eases of  the  Skin, 16 

Stelwagon— Essentials  of  Diseases  of 
the  Skin, 15 

SURGERY. 

An  American  Text-Book  of  Surgerj*,  2 
An  American  Year-Book  of  Medicine 

and  Surgery, .    .  3 

Beck— Fractures, 4 

Beck — Manual  of  Surgical  Asepsis,  .    .    .  4 

Da  Costa— Manual  of  Surgery-, 5 

International  Text-Book  of  Surgery,  .  8 

Keen— Operation  Blank, 8 

Keen — The  Surgical  Complications  and 

Sequels  of  Typhoid  Fever, 8 

Macdonald  —  Surgical     Diagnosis    and 

Treatment, 9 

Martin — Essentials  of    Minor    Surgery, 

Bandaging,  and  Venereal  Diseases,  .    .  15 

Martin — Essentials  of  Surgeiy, 15 

Moore — Orthopedic   Surgery, 10 

Nancrede — Principles  of  Surgery,  ...  10 

Pye — Bandaging  and  Surgical   Dressing,  11 

Scudder — Treatment  of  Fractures,   ...  12 

Senn — Genito-Urinary  Tuberculosis,   .    .  12 

Senn— Practical  Surgery, 12 

Senn — Syllabus  of  Surgery, 12 

Senn — Pathology  and  Surgical  Treat- 
ment  of  Tumors, ...  12 

\Varren — Surgical  Pathology  and  Ther- 
apeutics,    14 

Zuckerkandl  and  Da  Costa — Atlas  of 

Operative  Surgery, 16 

URINE  AND  URINARY  DISEASES. 

Ogden — Clinical      Examination     of    the 

Urine, 10 

Saundby — Renal  and  Urinary  Diseases,  11 
Wolf — Handbook  of  Urine  Examination,  22 
Wolff — Examination  of  Urine, 15 

MISCELLANEOUS. 

Abbott— Hygiene  of  Transmissible  Dis- 
eases,          3 

Bastin — Laboratory  Exercises  in  Bot- 
any,   4 

Golebiewski  and  Bailey— Atlas  of  Dis- 
eases Caused  by  Accidents,  .        .        .    .    17 
Gould  and    Pyle — Anomalies  and  Curi- 
osities of  .\Iedicine, 7 

Grafstrom — Massage, 7 

Keating — Examination  for  Life  Insur- 
ance,      8 

Pyle  — .V  .Manual  f)f  Personal  Hygiene,  .  \x 
Saunders'  .Medical  Hand-Atlases,  .  16,  17 
Saunders'  i'ocket  Medical  Formulary,  .  11 
Saunders'  (Jiicstion-Compends,  .  .  14,  15 
Stewart  and  Lawrence — Essentials  of 

Medical    l-^lectricity, 15 

Thornton  — Dose-Bf>ok   and    Manual   of 

Prescriptifin-Writing 13 

Van  Valzah  and  Nisbet— Diseases  of 
tlx-  Sioma<  h 13 


•  COLUMBIA  UNIVERSITY  LIBRARIES 


This  book  is  due  on  the  date  indicated  below,  or  at  the 
expiration  of  a  definite  period  after  the  date  of  borrowing, 
as  provided  by  the  rules  of  the  Library  or  by  special  ar- 
rangement with  the  Librarian  in  charge. 


AT 

DATE   BORROWED 

DATE   DUE 

DATE   BORROWED 

DATE  DUE 

JUl    2  3  1< 

tdS 

SEPH 

•  -< 

AT 

AT 

AT 

AT 

AT 

AT 

C2BI1  1*0)M100               1 

200  pages  0}  text. 

CloHi.  S'3-So  net. 

ATLAS  AND   EPITOME  pF  SPECIAL  PATHOLOGICAL  HIS= 
TOLOGY. 

By  Dr.  H.  Durck,  of  Munich.  Edited  by  LUDWIG  Hektoen,  M.  D.. 
Professor  of  Pathology,  Rush  Medical  College.  Chicago.  In  Two  Parts. 
Part  I.  Ready,  including  Circulatory,  Respiratory,  and  Gastro-intestinal 
Tract.  120  colored  figures  on  62  plates,  158  pages  of  text.  Part  IL  Ready 
Shortly.     Price  of  Part  I.,  $3.00  net. 

16 


Saunders'  Medical  Hand=Atlases. 


ATLAi 

By 


AT 


^ 


QM28 
!Jancrede 


% 


N15 
1899 


%^^ 


ACCI- 

''ddi- 

k. 
h, 


ATI 


ATI 


ATI 


ATI 


^^^^"iiiili ,1., «a^.^A;.,iacjk'ng  the  ana 


2002198908 


ATLAS  AND   EPITOME  OF  BACTERIOLOGY. 

Including  a  Hand-Book  of  Special  Bacterioiogic  Diai,'nosis.  By  Prof.  Dr. 
K.  B.  LEIfMANN  and  Dr.  R.  O.  Neumann,  of  Wurzburir.  From  the  Second 
Revised  German  Jiditioti.  llditcd  by  Geor(;e  H.  Weaver,  M.  D.,  Assistant 
Professor  of  Patholof^y  and  Bacteriology.  Rush  Medical  College,  Chicago. 
Two  volumes,  with  over  6oo  colored  lithographic  figures,  numerous  text- 
illustrations,  and  SOD  pages  of  tex*. 


ADDITIONAL  VOLUMES  IN  PREPARATION. 


